Adding upstream version 1.23.0.upstream/1.23.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4486 insertions, 0 deletions

diff --git a/doc/ms.ms b/doc/ms.ms
new file mode 100644
index 0000000..984c804
--- /dev/null
+++ b/doc/ms.ms
@@ -0,0 +1,4486 @@
+.\" This file is part of groff.
+.\"
+.\" groff is free software; you can redistribute it and/or modify it
+.\" under the terms of the GNU General Public License as published by
+.\" the Free Software Foundation, either version 3 of the License, or
+.\" (at your option) any later version.
+.\"
+.\" groff is distributed in the hope that it will be useful, but WITHOUT
+.\" ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+.\" or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
+.\" License for more details.
+.\"
+.\" You should have received a copy of the GNU General Public License
+.\" along with this program. If not, see <http://www.gnu.org/licenses/>.
+.
+.\" Handle font requests with families, for instance in tbl(1) tables.
+.if n \{\
+.  ftr CR B \" for a visible distinction from roman
+.  ftr CB B
+.  ftr CI I
+.  ftr CBI BI
+.  \" Redefine CW to use bold instead for a visible font change.
+.  als CW B
+.  \" The "document control settings" table imposes this minimum width.
+.  nr LL 87n
+.\}
+.\" This document doesn't require the minus sign (in Times) but we do
+.\" want a copy- and-pastable hyphen-minus.
+.ie '\*[.T]'cp1047' .char \- \N'96'
+.el                 .char \- \N'45'
+.\" A very limited output device might not have a dagger glyph.
+.fchar \[dg] *
+.nr PS 11
+.nr VS 13
+.ds FR 1
+.nr TC-MARGIN \w'00' \" expect 2-digit page numbers at most
+.ie t .nr PI 3.5n
+.el   .nr PI 4n
+.ND May 2023
+.EH '%''May 2023'
+.EF ''''
+.OH 'Using \f[I]groff\f[] with the \f[I]ms\f[] macros''%'
+.OF ''''
+.TL
+Using
+.BI groff
+with the
+.BI ms
+Macro Package
+.AU
+Larry Kollar
+.AI
+kollar@alltel.net
+.AU
+G.\& Branden Robinson
+.AI
+g.branden.robinson@gmail.com
+.AB no
+The
+.I ms
+(\[lq]manuscript\[rq]) package is suitable for the composition of
+letters,
+memoranda,
+reports,
+and books.
+.
+These
+.I groff
+macros feature cover page and table of contents generation,
+automatically numbered headings,
+several paragraph styles,
+a variety of text styling options,
+footnotes,
+and multi-column page layouts.
+.
+.I ms
+supports the
+.I tbl ,
+.I eqn ,
+.I pic ,
+and
+.I refer
+preprocessors for inclusion of tables,
+mathematical equations,
+diagrams,
+and standardized bibliographic citations.
+.
+This implementation is mostly compatible with the documented interface
+and behavior of AT&T Unix Version\~7
+.I ms .
+.
+Many extensions from 4.2BSD (Berkeley)
+.\" Few changes were made in 4.3, Tahoe, Reno, or 4.4.
+and Tenth Edition Research Unix have been recreated.
+.AE
+.
+.
+.\" ------------------------- End of cover page ------------------------
+.NH 1
+Introduction
+.XS
+Introduction
+.XE
+.
+.
+.LP
+The
+.I ms
+macros are the oldest surviving package for
+.I roff
+systems.\**
+.
+.FS
+While manual
+.I pages
+are older,
+early ones used macros supplanted by the
+.I man
+package of Seventh Edition Unix (1979).
+.
+.I ms
+shipped with Sixth Edition (1975) and was documented by Mike Lesk in a
+Bell Labs internal memorandum.
+.FE
+.
+While the
+.I man
+package was designed for brief reference documents,
+the
+.I ms
+macros are also suitable for longer works intended for printing and
+possible publication.
+.
+.
+.PP
+In this document,
+a right arrow (\[->]) is used to indicate a tab character in the input.
+.
+.
+.KS
+.NH 2
+Basic information
+.XS
+	Basic information
+.XE
+.
+.
+.LP
+.I ms
+documents are plain text files;
+prepare them with your preferred text editor.
+.
+If you're in a hurry to start,
+know that
+.I ms
+needs one of its macros called at the beginning of a document so that it
+can initialize.
+.
+A
+.I macro
+is a formatting instruction to
+.I ms.
+.
+Put a macro call on a line by itself.
+.
+Use
+.CW .PP
+if you want your paragraph's first line to be indented,
+or
+.CW .LP
+if you don't.
+.KE
+.
+.
+.PP
+After that,
+start typing normally.
+.
+It is a good practice to start each sentence on a new line,
+or to put two spaces after sentence-ending punctuation,
+so that the formatter knows where the sentence boundaries are.
+.
+You can separate paragraphs with further paragraphing macro calls,
+or with blank lines,
+and you can indent with tabs.
+.
+When you need one of the features mentioned earlier,
+return to this manual.
+.
+.
+.PP
+Format the document with the
+.I groff (1)
+command.
+.
+.I nroff (1)
+can be useful for previewing.
+.
+.
+.if n .ftr TI I
+.TS
+box center;
+Lf(CR)1 Lf(CB).
+$	editor radical.ms \f[TI]# vim, emacs, .\|.\|.
+$	nroff -ww -z -ms radical.ms \f[TI]# check for errors
+$	nroff \-ms radical.ms | less \-R
+$	groff \-T pdf \-ms radical.ms > radical.pdf
+$	see radical.pdf \f[TI]# or your favorite PDF viewer
+.TE
+.if n .ftr TI
+.
+.
+.PP
+Our
+.CW radical.ms
+document might look like this.
+.
+.
+.TS
+box center;
+Lf(CR).
+\&.LP
+Radical novelties are so disturbing that they tend to be
+suppressed or ignored, to the extent that even the
+possibility of their existence in general is more often
+denied than admitted.
+.sp
+\[->]That\[aq]s what Dijkstra said, anyway.
+.TE
+.
+.
+.LP
+.I ms
+exposes many aspects of document layout to user control via
+.I groff 's
+.I registers
+and
+.I strings,
+which store numbers and text,
+respectively.
+.
+Measurements in
+.I groff
+are expressed with a suffix called a
+.I "scaling unit."
+.
+.
+.TS
+box center;
+cb cb
+cf(CR) l .
+Scaling unit	Description
+_
+i	inches (\[sd])
+c	centimeters
+p	points (1/72\[sd])
+P	picas (1/6\[sd])
+v	\[lq]vees\[rq]; current vertical spacing
+m	\[lq]ems\[rq]; width of an \[lq]M\[rq] in the current font
+n	\[lq]ens\[rq]; one-half em
+.TE
+.
+.
+.PP
+Set registers with the
+.CW nr
+request
+and strings with the
+.CW ds
+request.
+.
+.I Requests
+are like macro calls;
+they go on lines by themselves and start with the
+.I "control character,"
+a dot
+.CW . ). (
+.
+The difference is that they directly instruct the formatter program,
+rather than the macro package.
+.
+We'll discuss a few as applicable.
+.
+It is wise to specify a scaling unit when setting any register that
+represents a length,
+size,
+or distance.
+.
+.
+.TS
+box center;
+lf(CR).
+\&.nr PS 10.5p \[rs]" Use 10.5\-point type.
+\&.ds FAM P    \[rs]" Use Palatino font family.
+.TE
+.
+.
+.LP
+In the foregoing,
+we see that
+.CW \[rs]"
+begins a comment.
+.
+This is an example of an
+.I "escape sequence,"
+the other kind of formatting instruction.
+.
+Escape sequences can appear anywhere.
+.
+They begin with the escape character
+.CW \[rs] ) (
+and are followed by at least one more character.
+.
+.I ms
+documents like this one tend to use only a few of
+.I groff 's
+many requests and escape sequences;
+see the
+.I groff (7)
+man page for complete lists.
+.
+.
+.TS
+box center;
+Cb Cb
+Lf(CR) Lx .
+Escape sequence	Description
+_
+\[rs]"	Begin comment; ignore remainder of line.
+\[rs]n[\f[I]reg\f[]]	T{
+Interpolate value of register
+.I reg .
+T}
+\[rs]*[\f[I]str\f[]]	T{
+Interpolate contents of string
+.I str .
+T}
+\[rs]*\f[I]s	T{
+abbreviation of
+.CW \[rs]*[\f[I]s\f[]] ;
+the name
+.I s
+must be only one character
+T}
+\[rs][\f[I]char\f[]]	T{
+Interpolate glyph of special character named
+.I char .
+T}
+\[rs]&	non-printing, zero-width dummy character
+\[rs]\[ti]	T{
+Insert an unbreakable space of adjustable width like a normal space.
+T}
+\[rs]|	T{
+Move horizontally by one-sixth em
+(\[lq]thin space\[rq]).
+T}
+.TE
+.
+.
+.PP
+Prefix any words that start with a dot
+.CW .\& ) (
+or neutral apostrophe
+.CW \[aq] ) (
+with
+.CW \[rs]&
+if they are at the beginning of an input line
+(or might become that way in editing)
+to prevent them from being interpreted as macro calls or requests.
+.
+Suffix
+.CW . ,
+.CW ? ,
+and
+.CW !\&
+with
+.CW \[rs]&
+when needed to cancel end-of-sentence detection.
+.
+.
+.TS
+box center;
+lf(CR).
+My exposure was \[rs]&.5 to \[rs]&.6 Sv of neutrons, said Dr.\[rs]&
+Wallace after the criticality incident.
+.TE
+.
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+General structure of an
+.BI ms
+document
+.XS
+General structure of an
+.I ms
+document
+.XE
+.
+.
+.LP
+The
+.I ms
+macro package expects a certain amount of structure:
+a well-formed document contains at least one paragraphing or heading
+macro call.
+.
+Longer documents have a structure as follows.
+.
+.
+.IP "\fBDocument type\fP"
+Calling the
+.CW RP
+macro at the beginning of your document puts the document description
+(see below)
+on a cover page.
+.
+Otherwise,
+.I ms
+places this information
+(if any)
+on the first page,
+followed immediately by the body text.
+.
+Some document types found in other
+.I ms
+implementations are specific to AT&T or Berkeley,
+and are not supported by
+.I "groff ms" .
+.
+.
+.IP "\fBFormat and layout\fP"
+By setting registers and strings,
+you can configure your document's typeface,
+margins,
+spacing,
+headers and footers,
+and footnote arrangement.
+.
+See section \[lq]Document control settings\[rq] below.
+.
+.
+.IP "\fBDocument description\fP"
+A document description consists of any of:
+a title,
+one or more authors' names and affiliated institutions,
+an abstract,
+and a date or other identifier.
+.
+See section \[lq]Document description macros\[rq] below.
+.
+.
+.IP "\fBBody text\fP"
+The main matter of your document follows its description
+(if any).
+.
+.I ms
+supports highly structured text consisting of paragraphs interspersed
+with multi-level headings
+(chapters,
+sections,
+subsections,
+and so forth)
+and augmented by lists,
+footnotes,
+tables,
+diagrams,
+and similar material.
+.
+See section \[lq]Body text\[rq] below.
+.
+.
+.IP "\fBTables of contents\fP"
+Macros enable the collection of entries for a table of contents
+(or index)
+as the material they discuss appears in the document.
+.
+You then call a macro to emit the table of contents at the end of
+your document.
+.
+The table of contents must necessarily follow the rest of the text since
+GNU
+.I troff
+is a single-pass formatter;
+it thus cannot determine the page number of a division of the text until
+it has been set and output.
+.
+Since
+.I ms
+output was designed for the production of hard copy,
+the traditional procedure was to manually relocate the pages containing
+the table of contents between the cover page and the body text.
+.
+Today,
+page resequencing is more often done in the digital domain.
+.
+An index works similarly,
+but because it typically needs to be sorted after collection,
+its preparation requires separate processing.
+.
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+Document control settings
+.XS
+Document control settings
+.XE
+.
+.
+.LP
+The document parameters below are presented in the syntax
+used to interpolate their values.
+.
+For any unsatisfactory default,
+define its register,
+string,
+or special character before calling any
+.I ms
+macro other than
+.CW RP .
+.
+The \[lq]Next\[rq] heading indicates that changes to the parameter are
+effective as of the next new element processed of the listed type.
+.
+For entries marked
+.I special ,
+see the discussion in the applicable section.
+.
+.
+.TS H
+box;
+cb | cb cb cb cb
+l | lf(CR)p-1 lx l lf(CR)p-1.
+Type	Parameter	Definition	Next	Default
+_
+.TH
+Margins	\[rs]n[PO]	Page offset (left margin)	page\
+	1i (0)\*{*\*}
+\^	\[rs]n[LL]	Line length	paragraph	\
+6.5i (65n)\*{*\*}
+\^	\[rs]n[LT]	Title line length	paragraph	\
+6.5i (65n)\*{*\*}
+\^	\[rs]n[HM]	Top (header) margin	page	1i
+\^	\[rs]n[FM]	Bottom (footer) margin	page	1i
+_
+T{
+Titles
+.br
+(headers,
+.br
+footers)
+T}	\[rs]*[LH]	Left header text	header	\f[I]empty
+\^	\[rs]*[CH]	Center header text	header	\-\[rs]n[%]\-
+\^	\[rs]*[RH]	Right header text	header	\f[I]empty
+\^	\[rs]*[LF]	Left footer text	footer	\f[I]empty
+\^	\[rs]*[CF]	Center footer text	footer	\f[I]empty
+\^	\[rs]*[RF]	Right footer text	footer	\f[I]empty
+_
+Text	\[rs]n[PS]	Type (point) size	paragraph	10p
+\^	\[rs]n[VS]	Vertical spacing	paragraph	12p
+\^	\[rs]n[HY]	Hyphenation mode	paragraph	6
+\^	\[rs]*[FAM]	Font family	paragraph	T
+_
+Paragraphs	\[rs]n[PI]	Indentation	paragraph	5n
+\^	\[rs]n[PD]	Paragraph distance (spacing)	paragraph\
+	0.3v \f[R](\f[]1v\f[R])\*{\[dg]\*}
+\^	\[rs]n[QI]	Quotation indentation	paragraph	5n
+\^	\[rs]n[PORPHANS]	# of initial lines kept	paragraph\
+	1
+_
+Headings	\[rs]n[PSINCR]	Type (point) size increment\
+	heading	1p
+\^	\[rs]n[GROWPS]	Size increase depth limit	heading	0
+\^	\[rs]n[HORPHANS]	# of following lines kept\
+	heading	1
+\^	\[rs]*[SN\-STYLE]	Numbering style (alias)	heading\
+	\[rs]*[SN\-DOT]
+_
+Footnotes	\[rs]n[FI]	Indentation	footnote	2n
+\^	\[rs]n[FF]	Format	footnote	0
+\^	\[rs]n[FPS]	Type (point) size	footnote\
+	\[rs]n[PS]\-2p
+\^	\[rs]n[FVS]	Vertical spacing	footnote\
+	\[rs]n[FPS]+2p
+\^	\[rs]n[FPD]	Paragraph distance (spacing)	footnote\
+	\[rs]n[PD]/2
+\^	\[rs]*[FR]	Line length ratio	\f[I]special	11/12
+_
+Displays	\[rs]n[DD]	Display distance (spacing)\
+	\f[I]special	0.5v \f[R](\f[]1v\f[R])\*{\[dg]\*}
+\^	\[rs]n[DI]	Display indentation	\f[I]special	0.5i
+_
+Other	\[rs]n[MINGW]	Minimum gutter width	page	2n
+\^	\[rs]n[TC\-MARGIN]	TOC page number margin width\
+	\f[CR]PX\f[] call	\[rs]w\[aq]000\[aq]
+\^	\[rs][TC\-LEADER]	TOC leader character\
+	\f[CR]PX\f[] call	.\[rs]h\[aq]1m\[aq]
+.TE
+.
+.
+.IP \*{*\*}
+Defaults vary by output device and paper format;
+the values shown are for typesetters using U.S.\& letter paper,
+and then terminals.
+.
+See section \[lq]Paper format\[rq] of the
+.I groff (1)
+man page.
+.
+.
+.IP \*{\[dg]\*}
+The
+.CW PD
+and
+.CW DD
+registers use the larger value if the vertical motion quantum of the
+output device is too coarse for the smaller one;
+usually,
+this is the case only for output to terminals and emulators thereof.
+.
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+Document description macros
+.XS
+Document description macros
+.XE
+.
+.
+.LP
+Only the simplest document lacks a title.\**
+.
+.FS
+Distinguish a document title from \[lq]titles\[rq],
+which are what
+.I roff
+systems call headers and footers collectively.
+.FE
+.
+As its level of sophistication
+(or complexity)
+increases,
+it tends to acquire a date of revision,
+explicitly identified authors,
+sponsoring institutions for authors,
+and,
+at the rarefied heights,
+an abstract of its content.
+.
+By default,
+.I ms
+arranges most of the document description
+(the title,
+author names and institutions,
+and abstract,
+but not the date)
+at the top of the first page.
+.
+.
+.PP
+Define these data by calling the macros below in the order shown;
+.CW .DA
+or
+.CW .ND
+can be called to set the document date
+(or other identifier)
+at any time before (a) the abstract,
+if present,
+or (b) its information is required in a header or footer.
+.
+Use of these macros is optional,
+except that
+.CW .TL
+is mandatory if any of
+.CW .RP ,
+.CW .AU ,
+.CW .AI ,
+or
+.CW .AB
+is called,
+and
+.CW .AE
+is mandatory if
+.CW .AB
+is called.
+.
+.
+.TS H
+box;
+lb lb
+lf(CR) lx.
+Macro	Description
+_
+.TH
+\&.RP \f[R][\f[I]option\f[] .\|.\|.]	T{
+Use the \[lq]report\[rq]
+(AT&T: \[lq]released paper\[rq])
+format for your document,
+creating a separate cover page.
+.
+If the optional
+.CW no\-\:\%repeat\-\:\%info
+argument is given,
+.I ms
+produces a cover page but does not repeat any of its information
+subsequently
+(but see the
+.CW DA
+macro below regarding the date).
+.
+Normally,
+.CW .RP
+sets the page number following the cover page to\~1.
+.
+Specifying the optional
+.CW no\-\:\%renumber
+argument suppresses this alteration.
+.
+Optional arguments can occur in any order.
+.
+.CW no
+is recognized as a synonym of
+.CW no\-\:\%repeat\-\:\%info
+for AT&T compatibility.
+T}
+_
+\&.TL	T{
+Specify the document title.
+.
+.I ms
+collects text on input lines following this call into the title
+until reaching
+.CW .AU ,
+.CW .AB ,
+or a heading or paragraphing macro call.
+T}
+_
+\&.AU	T{
+Specify an author's name.
+.
+.I ms
+collects text on input lines following this call into the author's name
+until reaching
+.CW .AI ,
+.CW .AB ,
+another
+.CW .AU ,
+or a heading or paragraphing macro call.
+.
+Call it repeatedly to specify multiple authors.
+T}
+_
+\&.AI	T{
+Specify the preceding author's institution.
+.
+An
+.CW .AU
+call is usefully followed by at most one
+.CW .AI
+call;
+if there are more,
+the last
+.CW .AI
+call controls.
+.
+.I ms
+collects text on input lines following this call into the author's
+institution until reaching
+.CW .AU ,
+.CW .AB ,
+or a heading or paragraphing macro call.
+T}
+_
+\&.DA \f[R][\f[I]x\f[] .\|.\|.\&]	T{
+Typeset the current date,
+or any
+.I x , arguments\~
+in the center footer,
+and,
+if
+.CW .RP
+is also called,
+left-aligned at the end of the document description on the cover page.
+T}
+_
+\&.ND \f[R][\f[I]x\f[] .\|.\|.\&]	T{
+Typeset the current date,
+or any
+.I x , arguments\~
+if
+.CW .RP
+is also called,
+left-aligned at the end of the document description on the cover page.
+.
+This is
+.I "groff ms" 's
+default.
+T}
+_
+\&.AB \f[R][\f[]no\f[R]]	T{
+Begin the abstract.
+.
+.I ms
+collects text on input lines following this call into the abstract
+until reaching an
+.CW .AE
+call.
+.
+By default,
+.I ms
+places the word \[lq]ABSTRACT\[rq] centered and in italics above the
+text of the abstract.
+.
+The optional argument
+.CW no
+suppresses this heading.
+T}
+_
+\&.AE	End the abstract.
+.TE
+.
+.
+.KS
+.LP
+An example document description,
+using a cover page,
+follows.
+.
+.
+.\" Wrap lines in the code example below at 64 columns.
+.TS
+box center;
+l.
+T{
+.nf
+.CW
+\&.RP
+\&.TL
+The Inevitability of Code Bloat in Commercial and Free Software
+\&.AU
+J.\[rs]& Random Luser
+\&.AI
+University of West Bumblefuzz
+\&.AB
+This report examines the long-term growth of the code bases in
+two large,
+popular software packages;
+the free Emacs and the commercial Microsoft Word.
+While differences appear in the type or order of features added,
+due to the different methodologies used,
+the results are the same in the end.
+\&.PP
+The free software approach is shown to be superior in that while
+free software can become as bloated as commercial offerings,
+free software tends to have fewer serious bugs and the added
+features are more in line with user demand.
+\&.AE
+.R
+\&.\|.\|.\|the rest of the paper\|.\|.\|.
+.fi
+T}
+.TE
+.KE
+.
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+Body text
+.XS
+Body text
+.XE
+.
+.
+.LP
+A variety of macros,
+registers,
+and strings can be used to structure and style the body of your
+document.
+.
+They organize your text into
+paragraphs,
+headings,
+footnotes,
+and inclusions of material such as tables and figures.
+.
+.
+.KS
+.NH 2
+Text settings
+.XS
+	Text settings
+.XE
+.
+.
+.LP
+The
+.CW FAM
+string,
+a GNU extension,
+sets the font family for body text;
+the default is
+.CW T \[rq]. \[lq]
+.
+The
+.CW PS
+and
+.CW VS
+registers set the type size and vertical spacing
+(distance between text baselines),
+respectively.
+.
+The font family and type size are ignored on terminal devices.
+.
+Setting these parameters before the first call of a heading,
+paragraphing,
+or (non-date) document description macro also applies them to headers,
+footers,
+and
+(for
+.CW FAM )
+footnotes.
+.
+.
+.PP
+Which font families are available depends on the output device;
+as a convention,
+.CW T
+selects a serif family (\[lq]Times\[rq]),
+.CW H
+a sans-serif family (\[lq]Helvetica\[rq]),
+and
+.CW C
+a monospaced family (\[lq]Courier\[rq]).
+.
+The man page for the output driver documents its font repertoire.
+.
+Consult the
+.I groff (1)
+man page for lists of available output devices and their drivers.
+.
+.
+.PP
+The
+.CW HY
+register defines the automatic hyphenation mode used with the
+.CW hy
+request.
+.
+Setting
+.CW \[rs]n[HY]
+.CW 0 "" to\~
+is equivalent to using the
+.CW nh
+request.
+.
+This is a Tenth Edition Research Unix extension.
+.KE
+.
+.
+.KS
+.NH 2
+Typographical symbols
+.XS
+	Typographical symbols
+.XE
+.
+.
+.LP
+.I ms
+provides a few strings to obtain typographical symbols not easily
+entered with the keyboard.
+.
+These and many others are available as special character escape
+sequences\*[-]see
+the
+.I groff_char (7)
+man page.
+.
+.TS
+box center;
+cb lb
+Lf(CR) Lx.
+String	Description
+_
+\[rs]*[\-]	Interpolate an em dash.
+_
+\[rs]*[Q]	T{
+Interpolate typographer's quotation marks where available,
+and neutral double quotes otherwise.
+.
+.CW \[rs]*[Q]
+is the left quote and
+.CW \[rs]*[U]
+the right.
+T}
+\[rs]*[U]	\^
+.TE
+.KE
+.
+.
+.KS
+.NH 2
+Paragraphs
+.XS
+	Paragraphs
+.XE
+.
+.
+.LP
+Paragraphing macros
+.I break ,
+or terminate,
+any pending output line so that a new paragraph can begin.
+.
+Several paragraph types are available,
+differing in how indentation
+applies to them:
+to left,
+right,
+or both margins;
+to the first output line of the paragraph,
+all output lines,
+or all but the first.
+.
+All paragraphing macro calls cause the insertion of vertical space in
+the amount stored in the
+.CW PD
+register,
+except at page or column breaks.
+.
+Alternatively,
+a blank input line breaks the output line and vertically spaces by one
+vee.
+.KE
+.
+.
+.PP
+The
+.CW PORPHANS
+register defines the minimum number of initial lines of any paragraph
+that must be kept together to avoid isolated lines at the bottom of a
+page.
+.
+If a new paragraph is started close to the bottom of a page,
+and there is insufficient space to accommodate
+.CW \[rs]n[PORPHANS]
+lines before an automatic page break,
+then a page break is forced before the start of the paragraph.
+.
+This is a GNU extension.
+.
+.
+.TS H
+box;
+lb lb
+lf(CR) lx.
+Macro	Description
+_
+.TH
+\&.LP	Set a paragraph without any (additional) indentation.
+_
+\&.PP	T{
+Set a paragraph with a first-line left indentation of
+.CW \[rs]n[PI] .
+T}
+_
+\&.IP \f[R][\f[I]marker\f[] [\f[I]width\f[]]]	T{
+Set a paragraph with a left indentation.
+.
+The optional
+.I marker
+is not indented and is empty by default.
+.
+It has several applications;
+see subsection \[lq]Lists\[rq] below.
+.
+.I width
+overrides the indentation amount in
+.CW \[rs]n[PI] ;
+its default unit is
+.CW n \[rq]. \[lq]
+.
+Once specified,
+.I width
+applies to further
+.CW .IP
+calls until specified again or a heading or different paragraphing macro
+is called.
+T}
+_
+\&.QP	T{
+Set a paragraph indented from both left and right margins by
+.CW \[rs]n[QI] .
+T}
+_
+T{
+\&.QS
+.br
+\&.QE
+T}	T{
+Begin
+.CW QS ) (
+and end
+.CW QE ) (
+a region where each paragraph is indented from both margins by
+.CW \[rs]n[QI] .
+.
+The text between
+.CW .QS
+and
+.CW .QE
+can be structured further by use of other paragraphing macros.
+T}
+_
+\&.XP	T{
+Set an \[lq]exdented\[rq] paragraph\[em]one with a left indentation of
+.CW \[rs]n[PI]
+on every line
+.I except
+the first
+(also known as a hanging indent).
+.
+This is a Berkeley extension.
+T}
+.TE
+.
+.
+.KS
+.PP
+The following example illustrates the use of paragraphing macros.
+.
+.
+.TS
+box center;
+l.
+T{
+.nf
+.CW
+\&.NH 2
+Cases used in the 2001 study
+\&.LP
+Two software releases were considered for this report.
+\&.PP
+The first is commercial software;
+the second is free.
+\&.IP \[rs][bu]
+Microsoft Word for Windows,
+starting with version 1.0 through the current version
+(Word 2000).
+\&.IP \[rs][bu]
+GNU Emacs,
+from its first appearance as a standalone editor through the
+current version (v20).
+See [Bloggs 2002] for details.
+\&.QP
+Franklin\[aq]s Law applied to software:
+software expands to outgrow both RAM and disk space over time.
+\&.SH
+Bibliography
+\&.XP
+Bloggs, Joseph R.,
+\&.I "Everyone\[aq]s a Critic" ,
+Underground Press, March 2002.
+A definitive work that answers all questions and criticisms
+about the quality and usability of free software.
+.R
+.fi
+T}
+.TE
+.KE
+.
+.
+.KS
+.NH 2
+Headings
+.XS
+	Headings
+.XE
+.
+.
+.LP
+Use headings to create a hierarchical structure for your document.
+.
+The
+.I ms
+macros print headings in
+.B bold
+using the same font family and,
+by default,
+type size as the body text.
+.
+Headings are available with and without automatic numbering.
+.
+Text on input lines following the macro call becomes the heading's
+title.
+.
+Call a paragraphing macro to end the heading text and start the
+section's content.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.NH [\f[I]depth\f[]]	T{
+Set an automatically numbered heading.
+.
+.I ms
+produces a numbered heading in the form
+.CW
+.I a .\c
+.I b .\c
+.R
+.I c .\|.\|.,
+to any level desired,
+with the numbering of each depth increasing automatically and being
+reset to zero when a more significant depth increases.
+.
+\[lq]1\[rq]\~is the most significant or coarsest division of the
+document.
+.
+Only non-zero values are output.
+.
+If
+.I depth
+is omitted,
+it is taken to be
+.CW 1 .
+.
+If you specify
+.I depth
+such that an ascending gap occurs relative to the previous
+.CW NH
+call\[em]that is,
+you \[lq]skip a depth\[rq],
+as by
+.CW ".NH\~1" \[rq] \[lq]
+and then
+.CW ".NH\~3" \[rq]\c \[lq]
+.I "groff ms" "" \[em]
+emits a warning on the standard error stream.
+T}
+\&.NH S \f[I]heading-depth-index\f[]\f[R] .\|.\|.\f[]	T{
+Alternatively,
+you can give
+.CW NH
+a first argument
+.CW S , of\~
+followed by integers to number the heading depths explicitly.
+.
+Further automatic numbering,
+if used,
+resumes using the specified indices as their predecessors.
+.
+.\" Although undocumented in Tuthill's 4.2BSD ms.diffs paper...
+This feature is a Berkeley extension.
+T}
+.TE
+.KE
+.
+.
+.PP
+An example may be illustrative.
+.
+.
+.TS
+box center;
+cb | cb
+lf(CR) | lB.
+Input	Result
+_
+T{
+.nf
+\&.NH 1
+Animalia
+\&.NH 2
+Arthropoda
+\&.NH 3
+Crustacea
+\&.NH 2
+Chordata
+\&.NH S 6 6 6
+Daimonia
+\&.NH 1
+Plantae
+.fi
+T}	T{
+.nf
+1.  Animalia
+.sp
+1.1.  Arthropoda
+.sp
+1.1.1.  Crustacea
+.sp
+1.2.  Chordata
+.sp
+6.6.6.  Daimonia
+.sp
+7.  Plantae
+.fi
+T}
+.TE
+.
+.
+.PP
+After
+.CW .NH
+is called,
+the assigned number is made available in the strings
+.CW SN\-DOT
+(as it appears in a printed heading with default formatting,
+followed by a terminating period)
+and
+.CW SN\-NO\-DOT
+(with the terminating period omitted).
+.
+These are GNU extensions.
+.
+.
+.PP
+You can control the style used to print numbered headings by defining an
+appropriate alias for the string
+.CW SN\-STYLE .
+.
+By default,
+.CW \[rs]*[SN\-STYLE]
+is aliased to
+.CW \[rs]*[SN\-DOT] .
+.
+If you prefer to omit the terminating period from numbers appearing in
+numbered headings,
+you may define the alias as follows.
+.
+.
+.TS
+box center;
+lf(CR).
+\&.als SN\-STYLE SN\-NO\-DOT
+.TE
+.
+.
+.LP
+Any such change in numbering style becomes effective from the next use
+of
+.CW .NH
+following redefinition of the alias for
+.CW \[rs]*[SN\-STYLE] .
+.
+The formatted number of the current heading is available in
+.CW \[rs]*[SN]
+(a feature first documented by Berkeley),
+which facilitates its inclusion in,
+for example,
+table captions,
+equation labels,
+and
+.CW .XS /\c
+.CW .XA /\c
+.CW .XE
+table of contents entries.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.SH [\f[I]depth\f[]]	T{
+Set an unnumbered heading.
+.
+The optional
+.I depth
+argument is a GNU extension indicating the heading depth corresponding
+to the
+.I depth
+argument of
+.CW .NH .
+.
+It matches the type size at which the heading is set to that of a
+numbered heading at the same depth when the
+.CW \[rs]n[GROWPS]
+and
+.CW \[rs]n[PSINCR]
+heading size adjustment mechanism is in effect.
+T}
+.TE
+.
+.
+.PP
+The
+.CW PSINCR
+register defines an increment in type size to be applied to a heading at
+a lesser depth than that specified in
+.CW \[rs]n[GROWPS] .
+.
+The value of
+.CW \[rs]n[PSINCR]
+should be specified in points with the
+.CW p
+scaling unit and may include a fractional component;
+for example,
+.
+.
+.TS
+box center;
+lf(CR).
+\&.nr PSINCR 1.5p
+.TE
+.
+.
+.LP
+sets a type size increment of 1.5 points.
+.
+.
+.PP
+The
+.CW GROWPS
+register defines the heading depth above which the type size increment
+set by
+.CW \[rs]n[PSINCR]
+becomes effective.
+.
+For each heading depth less than the value of
+.CW \[rs]n[GROWPS] ,
+the type size is increased by
+.CW \[rs]n[PSINCR] .
+.
+Setting
+.CW \[rs]n[GROWPS]
+to a value less than\~2 disables the incremental heading size feature.
+.
+.
+.PP
+In other words,
+if the value of
+.CW GROWPS
+register is greater than the
+.I depth
+argument to a
+.CW .NH
+or
+.CW .SH
+call,
+the type size of a heading produced by these macros increases by
+.CW \[rs]n[PSINCR]
+units over
+.CW \[rs]n[PS]
+multiplied by the difference of
+.CW \[rs]n[GROWPS]
+and
+.I depth .
+.
+.
+For example,
+the sequence
+.
+.TS
+box center;
+lf(CR).
+\&.nr PS 10
+\&.nr GROWPS 3
+\&.nr PSINCR 1.5p
+\&.NH 1
+Carnivora
+\&.NH 2
+Felinae
+\&.NH 3
+Felis catus
+\&.SH 2
+Machairodontinae
+.TE
+.
+.
+.LP
+will cause \[lq]1. Carnivora\[rq] to be printed in 13-point text,
+followed by \[lq]1.1. Felinae\[rq] in 11.5-point text,
+while \[lq]1.1.1. Felis catus\[rq] and all more deeply nested headings
+will remain in the 10-point text specified by the
+.CW PS
+register.
+.
+\[lq]Machairodontinae\[rq] is printed at 11.5 points,
+since it corresponds to heading depth\~2.
+.
+.
+.PP
+The
+.CW \[rs]n[HORPHANS]
+register operates in conjunction with the
+.CW NH
+and
+.CW SH
+macros to inhibit the printing of isolated headings at the bottom of a
+page;
+it specifies the minimum number of lines of the subsequent paragraph
+that must be kept on the same page as the heading.
+.
+If insufficient space remains on the current page to accommodate the
+heading and this number of lines of paragraph text,
+a page break is forced before the heading is printed.
+.
+Any display macro call or
+.I tbl ,
+.I pic ,
+or
+.I eqn
+region
+(see subsequent sections)
+between the heading and the subsequent paragraph suppresses this
+grouping.
+.
+.
+.\" The next table is huge and we need a lot of room for it, but we
+.\" can't use a keep because it's a boxed repeated-heading table.  Flush
+.\" the pending output line and demand half a page.
+.br
+.ne (\n[.p]u / 2u)
+.NH 2
+Typeface and decoration
+.XS
+	Typeface and decoration
+.XE
+.
+.
+.LP
+The
+.I ms
+macros provide a variety of ways to style text.
+.
+Attend closely to the ordering of arguments labeled
+.I pre
+and
+.I post,
+which is not intuitive.
+.
+Support for
+.I pre
+arguments is a GNU extension.\**
+.FS
+This idiosyncrasy arose through feature accretion;
+for example,
+the
+.CW B
+macro in Version\~6 Unix
+.I ms
+(1975) accepted only one argument,
+the text to be set in boldface.
+.
+By Version\~7 (1979) it recognized a second argument;
+in 1990,
+.I "groff ms"
+added a \*[Q]pre\*[U] argument,
+placing it third to avoid breaking support for older documents.
+.FE
+.
+.
+.TS H
+box;
+lb lb
+lf(CR) lx.
+Macro	Description
+_
+.TH
+\&.B \f[R][\f[I]text\f[] [\f[I]post\f[] [\f[I]pre\f[]]]]	T{
+Style
+.I text
+in
+.B bold ,
+followed by
+.I post
+in the previous font style without intervening space,
+and preceded by
+.I pre
+similarly.
+.
+Without arguments,
+.I ms
+styles subsequent text in bold
+until the next
+paragraphing,
+heading,
+or no-argument typeface macro call.
+T}
+_
+\&.R \f[R][\f[I]text\f[] [\f[I]post\f[] [\f[I]pre\f[]]]]	T{
+As
+.CW .B ,
+but use the roman style
+(upright text of normal weight)
+instead of bold.
+.
+Argument recognition is a GNU extension.
+T}
+_
+\&.I \f[R][\f[I]text\f[] [\f[I]post\f[] [\f[I]pre\f[]]]]	T{
+As
+.CW .B ,
+but use an
+.I italic
+or oblique style instead of bold.
+T}
+_
+\&.BI \f[R][\f[I]text\f[] [\f[I]post\f[] [\f[I]pre\f[]]]]	T{
+As
+.CW .B ,
+but use a
+.BI "bold italic"
+or bold oblique style instead of upright bold.
+.
+This is a Tenth Edition Research Unix extension.
+.\" possibly 9th, but definitely not Berkeley
+T}
+_
+\&.CW \f[R][\f[I]text\f[] [\f[I]post\f[] [\f[I]pre\f[]]]]	T{
+As
+.CW .B ,
+but use a
+.CW constant-width
+(monospaced) roman typeface instead of bold.
+.
+This is a Tenth Edition Research Unix extension.
+.\" possibly 9th, but definitely not Berkeley
+T}
+_
+\&.BX \f[R][\f[I]text\f[]]	T{
+Typeset
+.I text
+and draw a
+.BX box
+around it.
+.
+On terminal devices,
+reverse video is used instead
+(see the implementation note below).
+.
+If you want
+.I text
+to contain space,
+use unbreakable space or horizontal motion escape sequences
+.CW \[rs]\[ti] , (
+.CW \[rs]\c
+.I space ,
+.CW \[rs]\[ha] ,
+.CW \[rs]| ,
+.CW \[rs]0 ,
+or
+.CW \[rs]h ).
+T}
+_
+\&.UL \f[R][\f[I]text\f[] [\f[I]post\f[]]]	T{
+Typeset
+.I text
+with an
+.UL underline .
+.
+.I post,
+if present,
+is set after
+.I text
+with no intervening space.
+T}
+_
+\&.LG	T{
+Set subsequent text in
+.LG
+larger type
+.NL
+(2\~points larger than the current size)
+until the next
+type size,
+paragraphing,
+or heading macro call.
+.
+You can
+.LG
+specify this macro
+.LG
+multiple times
+.NL
+to enlarge the type size as needed.
+T}
+_
+\&.SM	T{
+Set subsequent text in
+.SM
+smaller type
+.NL
+(2\~points smaller than the current size)
+until the next
+type size,
+paragraphing,
+or heading macro call.
+.
+You can
+.SM
+specify this macro
+.SM
+multiple times
+.NL
+to reduce the type size as needed.
+T}
+_
+\&.NL	T{
+Set subsequent text at the normal type size
+.CW \[rs]n[PS] ). (
+T}
+.TE
+.
+.
+.PP
+.I pre
+and
+.I post
+arguments
+are typically used to simplify the attachment of punctuation to styled
+words.
+When
+.I pre
+is used,
+a hyphenation control escape sequence
+.CW \[rs]%
+that would ordinarily start
+.I text
+must start
+.I pre
+instead to have the desired effect.
+.
+.TS
+box center;
+Cb Cb
+Lf(CR) L.
+Input	Result
+T{
+.na
+.nh
+The CS course\[aq]s students found one C language keyword
+.br
+\&.CW static ) \[rs]%(
+.br
+most troublesome.
+T}	T{
+The CS course's students found one C language keyword
+.CW static ) \%(
+most troublesome.
+T}
+.TE
+.
+.KS
+You can use the output line continuation escape sequence
+.CW \[rs]c
+to achieve the same result.
+.
+It is also portable to some older
+.I ms
+implementations. \" DWB 3.3 ms: no; Heirloom Doctools ms: yes
+.
+.TS
+box center;
+Cb Cb
+Lf(CR) L.
+Input	Result
+T{
+.na
+.nh
+The CS course\[aq]s students found one C language keyword
+.br
+\[rs]%(\[rs]c
+.br
+\&.CW static )
+.br
+most troublesome.
+T}	T{
+The CS course's students found one C language keyword
+\%(\c
+.CW static )
+most troublesome.
+T}
+.TE
+.KE
+.
+.
+.PP
+Rather than calling the
+.CW CW
+macro,
+in
+.I "groff ms"
+you might prefer to change the font family to Courier by setting
+.CW \[rs]*[FAM]
+to
+.CW C \[rq]. \[lq]
+.
+You can then use all four style macros above,
+returning to the default family (Times) with
+.CW ".ds FAM T" \[rq]. \[lq]
+.
+Because changes to
+.CW \[rs]*[FAM]
+take effect only at the next paragraph,
+this document uses
+.CW .CW
+to \[lq]inline\[rq] a change to the font family,
+marking syntactical elements of
+.I ms
+and
+.I groff .
+.
+.
+.KS
+.PP
+.I "groff ms"
+also offers strings to begin and end super- and subscripting.
+.
+These are GNU extensions.
+.
+.
+.TS
+box;
+lb lb
+lf(CR) lx.
+String	Description
+_
+\[rs]*{	Begin superscripting.
+\[rs]*}	End superscripting.
+_
+\[rs]*<	Begin subscripting.
+\[rs]*>	End subscripting.
+.TE
+.KE
+.
+.
+.nr PS -2
+.nr VS -2
+.LP
+.B1
+.hy 0
+.I "Implementation note:"
+In
+.CW nroff
+mode,
+the
+.CW BX
+macro \[lq]boxes\[rq] its argument by bracketing it with
+.I groff
+extension escape sequences to set the foreground color to black and the
+background to white and then reset them to their previous values;
+the terminal output driver,
+.I grotty (1),
+converts these to ISO\~6429 color escape sequences,
+which may be ignored or mishandled by some terminals,
+or may be disabled by
+.I grotty 's
+.CW \-c
+option.
+.
+Further,
+if the terminal is set up to use these colors in those roles already,
+.CW .BX
+will cause no visible effect in the output.
+.
+Surmounting these challenges would require adding features to
+.I grotty ,
+for instance to provide a mechanism to request ISO\~6429's
+\[lq]standout\[rq] mode \" That's "smso" and "rmso" in terminfo.
+(often supported on monochrome terminals),
+or to replace the presumed support of the terminal for ISO\~6429 escape
+sequences with the use of a library that can query the capabilities of
+the terminal and adapt the output sent to the device accordingly.
+.
+(Practically,
+this likely means adding a dependency on
+.CW libtinfo .)
+.
+Contact the
+.I groff
+development mailing list if you'd like to contribute.
+.sp \n[PD]/2
+.B2
+.nr PS +2
+.nr VS +2
+.
+.
+.NH 2
+Lists
+.XS
+	Lists
+.XE
+.
+.
+.LP
+The
+.I marker
+argument to the
+.CW IP
+macro can be employed to present a variety of lists;
+for instance,
+you can use a bullet glyph
+.CW \[rs][bu] ) (
+for unordered lists,
+a number
+(or auto-incrementing register)
+for numbered lists,
+or a word or phrase for glossary-style or definition lists.
+.
+If you set the paragraph indentation register
+.CW PI
+before calling
+.CW IP ,
+you can later reorder the items in the list without having to ensure
+that a
+.I width
+argument remains affixed to the first call.
+.
+.
+.TS H
+box center;
+cb cb
+lf(CR) l .
+Input	Result
+_
+.TH
+T{
+.nf
+\&.nr PI 2n
+A bulleted list:
+\&.IP \[rs][bu]
+lawyers
+\&.IP \[rs][bu]
+guns
+\&.IP \[rs][bu]
+money
+.fi
+T}	T{
+.nr PI 2n
+A bulleted list:
+.IP \[bu]
+lawyers
+.IP \[bu]
+guns
+.IP \[bu]
+money
+T}
+_
+T{
+.nf
+\&.nr step 0 1
+\&.nr PI 3n
+A numbered list:
+\&.IP \[rs]n+[step].
+lawyers
+\&.IP \[rs]n+[step].
+guns
+\&.IP \[rs]n+[step].
+money
+.fi
+T}	T{
+.nr step 0 1
+.nr PI 3n
+A numbered list:
+.IP \n+[step].
+lawyers
+.IP \n+[step].
+guns
+.IP \n+[step].
+money
+T}
+_
+T{
+.nf
+A glossary-style list:
+\&.IP lawyers 0.4i
+Two or more attorneys.
+\&.IP guns
+Firearms,
+preferably large-caliber.
+\&.IP money
+Gotta pay for those
+lawyers and guns!
+.fi
+T}	T{
+A glossary-style list:
+.
+.IP lawyers 0.4i
+Two or more attorneys.
+.IP guns
+Firearms,
+preferably large-caliber.
+.IP money
+Gotta pay for those lawyers and guns!
+T}
+.TE
+.
+.
+.PP
+In the enumerated list example,
+we employed the
+.CW nr
+request to create a register of our own,
+.CW step .
+.
+We initialized it to zero and assigned it an auto-increment of 1.
+.
+Each time we use the escape sequence
+.CW \[rs]n+[PI]
+(note the plus sign),
+the formatter applies the increment just before interpolating the
+register's value.
+.
+Preparing the
+.CW PI
+register as well enables us to rearrange the list without the tedium of
+updating macro calls.
+.
+.
+.PP
+In the glossary example,
+observe how the
+.CW IP
+macro places the definition on the same line as the term if it has
+enough space.
+.
+If this is not what you want,
+there are a few workarounds we will illustrate by modifying the example.
+.
+First,
+you can use a
+.CW br
+request to force a break after printing the term or label.
+.
+Second,
+you could apply the
+.CW \[rs]p
+escape sequence to force a break.
+.
+The space following the escape sequence is important;
+if you omit it,
+.I groff
+prints the first word of the paragraph text on the same line as the term
+or label
+(if it fits)
+.I then
+breaks the line.
+.
+Finally,
+you may append a horizontal motion to the marker with the
+.CW \[rs]h
+escape sequence;
+using the same amount as the indentation will ensure that the marker is
+too wide for
+.I groff
+to treat it as \[lq]fitting\[rq] on the same line as the paragraph text.
+.
+.
+.TS
+box center;
+cb | cb | cb
+lf(CR) | lf(CR)  | lf(CR).
+Approach #1	Approach #2	Approach #3
+_
+T{
+.nf
+\&.IP guns
+\&.br
+Firearms,
+.fi
+T}	T{
+.nf
+\&.IP guns
+\[rs]p Firearms,
+.fi
+T}	T{
+.nf
+\&.IP guns\[rs]h\[aq]0.4i\[aq]
+Firearms,
+.fi
+T}
+_
+.T&
+cb s s
+l s s.
+Result
+_
+T{
+A glossary-style list:
+.
+.IP lawyers 0.4i
+Two or more attorneys.
+.IP guns\h\[aq]0.4i\[aq] 0.4i
+Firearms,
+preferably large-caliber.
+.IP money
+Gotta pay for those lawyers and guns!
+T}
+.TE
+.
+.
+.NH 2
+Indented regions
+.XS
+	Indented regions
+.XE
+.
+.
+.LP
+You may need to indent a region of text while otherwise formatting it
+normally.
+.
+Indented regions can be nested;
+you can change
+.CW \[rs]n[PI]
+before each call to vary the amount of inset.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.RS	T{
+Begin a region where headings,
+paragraphs,
+and displays are indented (further) by
+.CW \[rs]n[PI] .
+T}
+\&.RE	T{
+End the (next) most recent indented region.
+T}
+.TE
+.
+.
+.PP
+This feature enables you to easily line up text under hanging and
+indented paragraphs.
+.
+For example,
+you may wish to structure lists hierarchically.
+.
+.
+.KS
+.TS
+box center;
+cb cb
+lf(CR)8 l .
+Input	Result
+_
+T{
+.nf
+.CW
+\&.IP \[rs][bu] 2
+Lawyers:
+\&.RS
+\&.IP \[rs][bu]
+Dewey,
+\&.IP \[rs][bu]
+Cheatham,
+and
+\&.IP \[rs][bu]
+Howe.
+\&.RE
+\&.IP \[rs][bu]
+Guns
+.R
+\&.\|.\|.
+.fi
+T}	T{
+.IP \[bu] 2
+Lawyers:
+.RS
+.IP \[bu]
+Dewey,
+.IP \[bu]
+Cheatham,
+and
+.IP \[bu]
+Howe.
+.RE
+.IP \[bu]
+Guns
+\&.\|.\|.
+T}
+.TE
+.KE
+.
+.
+.NH 2
+Keeps, boxed keeps, and displays
+.XS
+	Keeps, boxed keeps, and displays
+.XE
+.
+.
+.LP
+On occasion,
+you may want to
+.I keep
+several lines of text,
+or a region of a document,
+together on a single page,
+preventing an automatic page break within certain boundaries.
+.
+This can cause a page break to occur earlier than it normally would.
+.
+For example,
+you may want to keep two paragraphs together,
+or a paragraph that refers to a table,
+list,
+or figure adjacent to the item it discusses.
+.
+.I ms
+provides the
+.CW KS
+and
+.CW KE
+macros for this purpose.
+.
+.
+.PP
+You can alternatively specify a
+.I "floating keep:"
+if a keep cannot fit on the current page,
+.I ms
+holds its contents and allows material following the keep
+(in the source document)
+to fill the remainder of the current page.
+.
+When the page breaks,
+whether by reaching the end or
+.CW bp
+request,
+.I ms
+puts the floating keep at the beginning of the next page.
+.
+This is useful for placing large graphics or tables that do not need to
+appear exactly where they occur in the source document.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.KS	Begin a keep.
+\&.KF	Begin a floating keep.
+_
+\&.KE	End (floating) keep.
+.TE
+.
+.
+.PP
+As an alternative to the keep mechanism,
+the
+.CW ne
+request forces a page break if there is not at least the amount of
+vertical space specified in its argument remaining on the page.
+.
+One application of
+.CW ne
+is to reserve space on the page for a figure or illustration to be
+included later.
+.
+.
+.KS
+.PP
+A
+.I "boxed keep"
+has a frame drawn around it.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.B1	Begin a keep with a box drawn around it.
+\&.B2	End boxed keep.
+.TE
+.KE
+.
+.
+.KS
+.LP
+Boxed keep macros cause breaks;
+if you need to box a word or phrase within a line,
+see the
+.CW BX
+macro in section \[lq]Typeface and decoration\[rq] above.
+.
+Box lines are drawn as close as possible to the text they enclose so
+that they are usable within paragraphs.
+.
+If you wish to place one or more paragraphs in a boxed keep,
+you may improve their appearance by calling
+.CW .B1
+after the first paragraphing macro,
+and by adding a small amount of vertical space before calling
+.CW .B2 .
+.
+.
+.TS
+box center;
+lf(CR).
+\&.LP
+\&.B1
+\&.I Warning:
+Happy Fun Ball may suddenly accelerate to dangerous speeds.
+\&.sp \[rs]n[PD]/2 \[rs]" space by half the inter-paragraph distance
+\&.B2
+.TE
+.KE
+.
+.
+.LP
+If you want a boxed keep to float,
+you will need to enclose the
+.CW .B1
+and
+.CW .B2
+calls within a pair of
+.CW .KF
+and
+.CW .KE
+calls.
+.
+.
+.PP
+.I Displays
+turn off filling;
+lines of verse or program code are shown with their lines broken as in
+the source document without requiring
+.CW br
+requests between lines.
+.
+Displays can be kept on a single page or allowed to break across pages.
+.
+The
+.CW DS
+macro begins a kept display of the layout specified in its first
+argument;
+non-kept displays are begun with dedicated macros corresponding to their
+layout.
+.
+.
+.TS
+box;
+cb s | cb
+cb cb | ^
+lf(CR) lf(CR) | lx .
+Display macro	Description
+With keep	Without keep
+_
+\&.DS L	\&.LD	Begin left-aligned display.
+\&.DS \f[R][\f[]I\f[R] [\,\f[I]indent\/\f[]]]	\
+\&.ID \f[R][\,\f[I]indent\/\f[]]	T{
+Begin display indented by
+.I indent
+if given,
+.CW \[rs]n[DI]
+otherwise.
+T}
+\&.DS B	\&.BD	T{
+Begin block display
+(left-aligned with longest line centered).
+T}
+\&.DS C	\&.CD	Begin centered display.
+\&.DS R	\&.RD	T{
+Begin right-aligned display.
+This is a GNU extension.
+T}
+_
+.T&
+cf(CR) s | lx .
+\&.DE	End any display.
+.TE
+.
+.
+.PP
+The distance stored in
+.CW \[rs]n[DD]
+is inserted before and after each pair of display macros;
+this is a Berkeley extension.
+.
+In
+.I "groff ms" ,
+this distance replaces any adjacent inter-paragraph distance
+or subsequent spacing prior to a section heading.
+.
+The
+.CW DI
+register is a GNU extension;
+its value is an indentation applied to displays created with
+.CW .DS
+and
+.CW .ID
+without arguments,
+to
+.CW .DS\~I \[rq] \[lq]
+without an indentation argument,
+and to equations set with
+.CW .EQ\~I \[rq]. \[lq]
+.
+Changes to either register take effect at the next display boundary.
+.
+.
+.KS
+.NH 2
+Tables, figures, equations, and references
+.XS
+	Tables, figures, equations, and references
+.XE
+.LP
+The
+.I ms
+package is often used with the
+.I tbl ,
+.I pic ,
+.I eqn ,
+and
+.I refer
+preprocessors.
+.
+The
+.CW \[rs]n[DD]
+distance is also applied to regions of the document preprocessed with
+.I tbl ,
+.I pic ,
+and
+.I eqn .
+.
+Mark text meant for preprocessors by enclosing it in pairs of tokens as
+follows,
+with nothing between the dot and the macro name.
+.
+The preprocessors match these tokens only at the start of an input line.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Tag pair	Description
+_
+T{
+\&.TS
+.R
+.CW H ] [
+.CW
+.br
+\&.TE
+T}	T{
+Demarcate a table to be processed by the
+.I tbl
+preprocessor.
+.
+The optional
+.CW H
+argument to
+.CW .TS
+instructs
+.I ms
+to repeat table rows
+(often column headings)
+at the top of each new page the table spans,
+if applicable;
+calling the
+.CW TH
+macro marks the end of such rows.
+.
+The GNU
+.I tbl (1)
+man page provides a comprehensive reference to the preprocessor and
+offers examples of its use.
+T}
+_
+T{
+\&.PS
+.br
+\&.PE
+.br
+\&.PF
+T}	T{
+.CW .PS
+begins a picture to be processed by the
+.I pic
+preprocessor;
+either of
+.CW .PE
+or
+.CW .PF
+ends it,
+the latter with \[lq]flyback\[rq] to the vertical position at its top.
+.
+You can create
+.I pic
+input manually or with a program such as
+.I xfig (1).
+T}
+_
+T{
+\&.EQ
+.R
+.I align \~[\c [
+.I label ]]
+.CW
+.br
+\&.EN
+T}	T{
+Demarcate an equation to be processed by the
+.I eqn
+preprocessor.
+.
+The equation is centered by default;
+.I align
+can be
+.CW C ,
+.CW L ,
+or
+.CW I
+to (explicitly) center,
+left-align,
+or indent it by
+.CW \[rs]n[DI] ,
+respectively.
+.
+If specified,
+.I label
+is set right-aligned.
+T}
+_
+T{
+\&.[
+.br
+\&.]
+T}	T{
+Demarcate a bibliographic citation to be processed by the
+.I refer
+preprocessor.
+.
+The GNU
+.I refer (1)
+man page provides a comprehensive reference to the preprocessor and the
+format of its bibliographic database.
+T}
+.TE
+.KE
+.
+.
+.PP
+When
+.I refer
+emits collected references
+(as might be done on a \[lq]Works Cited\[rq] page),
+it interpolates the string
+.CW \[rs]*[REFERENCES]
+as an unnumbered heading
+.CW .SH ). (
+.
+.
+.KS
+.PP
+The following is an example of how to set up a table that may print
+across two or more pages.
+.
+.
+.TS
+box center;
+l .
+T{
+.nf
+.CW
+\&.TS H
+allbox;
+Cb | Cb .
+Part\[->]Description
+_
+\&.TH
+\&.T&
+L | Lx .
+GH-1978\[->]Fribulating gonkulator
+.R
+\&.\|.\|.\|the rest of the table follows\|.\|.\|.
+.CW
+\&.TE
+.R
+.fi
+T}
+.TE
+.
+.
+Attempting to place a multi-page table inside a keep can lead to
+unpleasant results,
+particularly if the
+.I tbl
+.CW allbox
+option is used.
+.KE
+.
+.
+.PP
+Mathematics can be typeset using the language of the
+.I eqn
+preprocessor.
+.
+.
+.TS
+box center;
+Lf(CR).
+\&.EQ C (\[rs]*[SN\-NO\-DOT]a)
+p \[ti] = \[ti] q sqrt { 1 + \[ti] ( x / q sup 2 ) }
+\&.EN
+.TE
+.
+.
+This input formats a labelled equation.
+.
+We used the
+.CW SN\-NO\-DOT
+string to base the equation label on the current heading number,
+giving us more flexibility to reorganize the document.
+.
+.
+.EQ C (\*[SN-NO-DOT]a)
+p ~ = ~ q sqrt { 1 + ~ ( x / q sup 2 ) }
+.EN
+.
+Use
+.I groff
+options
+to run preprocessors on the input:
+.CW \-e
+for
+.I eqn ,
+.CW \-p
+for
+.I pic ,
+.CW \-R
+for
+.I refer ,
+and
+.CW \-t
+for
+.I tbl.
+.
+.
+.KS
+.NH 2
+Footnotes
+.XS
+	Footnotes
+.XE
+.
+.
+.LP
+.\" The following sentence is used below as an example as well.  Keep it
+.\" in sync.
+A footnote is typically anchored to a place in the text with a
+.I marker,
+which is a small integer,\**
+.FS
+like this numeric footnote
+.FE
+a symbol,\*{\[dg]\*}
+.FS \[dg]
+like this symbolic footnote
+.FE
+or arbitrary user-specified text.
+.
+.
+.TS
+box;
+lb lb
+lf(CR) lx.
+String	Description
+_
+\[rs]**	T{
+Place an
+.I "automatic number,"
+an automatically updated numeric footnote marker,
+in the text.
+.
+Each time this string is interpolated,
+the number it produces increments by one.
+.
+Automatic numbers start at 1.
+.
+This is a Berkeley extension.
+T}
+.TE
+.KE
+.
+.
+.PP
+Enclose the footnote text in
+.CW FS
+and
+.CW FE
+macro calls to set it at the nearest available \[lq]foot\[rq],
+or bottom,
+of a text column or page.
+.
+.
+.TS
+box;
+cb cb
+lfCR lx .
+Macro	Description
+_
+\&.FS \f[R][\f[I]marker\f[]]	T{
+Begin a footnote.
+.
+The
+.CW FS\-MARK
+hook
+(see below)
+is called with any supplied
+.I marker
+argument,
+which is then also placed at the beginning of the footnote text.
+.
+If
+.I marker
+is omitted,
+the next pending automatic number enqueued by interpolation of the
+.CW *
+string is used,
+and if none exists,
+nothing is prefixed.
+.
+T}
+_
+\&.FE	End footnote text.
+.TE
+.
+.
+.PP
+You may not desire automatically numbered footnotes in spite of their
+convenience.
+.
+You can indicate a footnote with a symbol or other text by specifying
+its marker at the appropriate place
+(for example,
+by using
+.CW \[rs][dg]
+for the dagger glyph)
+.I and
+as an argument to the
+.CW FS
+macro.
+.
+Such manual marks should be repeated as arguments to
+.CW .FS
+or as part of the footnote text to disambiguate their correspondence.
+.
+You may wish to use
+.CW \[rs]*{
+and
+.CW \[rs]*}
+to superscript the marker at the anchor point,
+in the footnote text,
+or both.
+.
+.
+.PP
+.I "groff ms"
+provides a hook macro,
+.CW FS\-MARK ,
+for user-determined operations to be performed when the
+.CW FS
+macro is called.
+.
+It is passed the same arguments as
+.CW FS
+itself.
+.
+An application of
+.CW FS\-MARK
+is anchor placement for a hyperlink reference,
+so that a footnote can link back to its referential context.\**
+.
+.FS
+\[lq]Portable Document Format Publishing with GNU Troff\[rq],
+.I pdfmark.ms
+in the
+.I groff
+distribution,
+uses this technique.
+.FE
+.
+By default,
+this macro has an empty definition.
+.
+.CW FS\-MARK
+is a GNU extension.
+.
+.
+.PP
+The following input was used to produce the first sentence in this
+section.
+.
+.
+.TS
+box center;
+lfCR.
+A footnote is anchored to a place in the text with a
+\&.I marker,
+which is a small integer,\[rs]**
+\&.FS
+like this numeric footnote
+\&.FE
+a symbol,\[rs]*{\[rs][dg]\[rs]*}
+\&.FS \[rs][dg]
+like this symbolic footnote
+\&.FE
+or arbitrary user-specified text.
+.TE
+.
+.
+.PP
+Footnotes can be safely used within keeps and displays,
+but you should avoid using automatically numbered footnotes within
+floating keeps.
+.
+You can place a second
+.CW \[rs]**
+interpolation between a
+.CW \[rs]**
+and its corresponding
+.CW .FS
+call as long as each
+.CW .FS
+call occurs
+.I after
+the corresponding
+.CW \[rs]**
+and occurrences of
+.CW .FS
+are in the same order as corresponding occurrences of
+.CW \[rs]** .
+.
+.
+.PP
+Footnote text is formatted as paragraphs are,
+using analogous parameters.
+.
+The registers
+.CW FI ,
+.CW FPD ,
+.CW FPS ,
+and
+.CW FVS
+correspond to
+.CW PI ,
+.CW PD ,
+.CW PS ,
+and
+.CW VS ,
+respectively;
+.CW FPD ,
+.CW FPS ,
+and
+.CW FVS
+are GNU extensions.
+.
+.
+.KS
+.PP
+The
+.CW FF
+register controls the formatting of automatically numbered footnote
+paragraphs,
+and those for which
+.CW .FS
+is given a
+.I marker
+argument,
+at the bottom of a column or page as follows.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+\f[CB]FF\f[] value	Description
+_
+0	T{
+Set an automatic number as a superscript
+(on typesetter devices)
+or surrounded by square brackets
+(on terminals).
+.
+The footnote paragraph is indented as with
+.CW .PP
+if there is an
+.CW .FS
+argument or an automatic number,
+and as with
+.CW .LP
+otherwise.
+.
+This is the default.
+T}
+1	T{
+As
+.CW 0 ,
+but set the marker as regular text,
+and follow an automatic number with a period.
+T}
+2	T{
+As
+.CW 1 ,
+but without indentation
+(like
+.CW .LP ).
+T}
+3	T{
+As
+.CW 1 ,
+but set the footnote paragraph with the marker hanging
+(like
+.CW .IP ).
+T}
+.TE
+.KE
+.
+.
+.PP
+The default footnote line length is 11/12ths of the normal line length
+for compatibility with the expectations of historical
+.I ms
+documents;
+you may wish to set
+.CW \[rs]*[FR]
+to
+.CW 1
+to align with contemporary typesetting practices.
+.
+In the past,\**
+.FS
+Unix
+Version\~7
+.I ms ,
+its descendants,
+and
+.I "groff ms"
+prior to version 1.23.0
+.FE
+an
+.CW FL
+register was used for the line length in footnotes;
+however,
+setting this register at document initialization time had no effect on
+the footnote line length in multi-column arrangements.\**
+.
+.FS
+You could reset it after each call to
+.CW .1C ,
+.CW .2C ,
+or
+.CW .MC .
+.FE
+.
+.
+.PP
+.CW \[rs]*[FR]
+should be used in preference to
+.CW \[rs]n[FL]
+in contemporary documents.
+.
+The footnote line length is effectively computed as
+.I column-width "" \[lq]
+.CW "\~*\~\[rs]*[FR]" \[rq].
+.
+If an absolute footnote line length is required,
+recall that arithmetic expressions in the
+.I roff
+language are evaluated strictly from left to right,
+with no operator precedence
+(parentheses are honored).
+.
+.
+.TS
+box center;
+lf(CR).
+\&.ds FR 0+3i \[rs]" Set footnote line length to 3 inches.
+.TE
+.
+.
+.LP \" continuing previous paragraph
+Changes to the footnote length ratio
+.CW \[rs]*[FR]
+take effect with the next footnote written in single-column
+arrangements,
+but on the next page in multiple-column contexts.
+.
+.
+.KS
+.NH 2
+Language and localization
+.XS
+	Language and localization
+.XE
+.
+.
+.LP
+.I "groff ms"
+provides several strings that you can customize for your own purposes,
+or redefine to adapt the macro package to languages other than English.
+.
+It is already localized for
+.\" cs, de, fr, it, sv
+Czech,
+German,
+French,
+Italian,
+and
+Swedish.
+.
+Load the desired localization macro package after
+.I ms ;
+see the
+.I groff_tmac (5)
+man page.
+.
+.
+.TS
+box center;
+lf(CR).
+$ \f[CB]groff \-ms \-mfr bienvenue.ms
+.TE
+.
+.
+.PP
+The following strings are available.
+.
+.TS
+box center;
+cb lb
+lf(CR) lf(CR) .
+String	Default
+_
+\[rs]*[REFERENCES]	References
+\[rs]*[ABSTRACT]	\[rs]f[I]ABSTRACT\[rs]f[]
+\[rs]*[TOC]	Table of Contents
+\[rs]*[MONTH1]	January
+\[rs]*[MONTH2]	February
+\[rs]*[MONTH3]	March
+\[rs]*[MONTH4]	April
+\[rs]*[MONTH5]	May
+\[rs]*[MONTH6]	June
+\[rs]*[MONTH7]	July
+\[rs]*[MONTH8]	August
+\[rs]*[MONTH9]	September
+\[rs]*[MONTH10]	October
+\[rs]*[MONTH11]	November
+\[rs]*[MONTH12]	December
+.TE
+.
+.
+.PP
+The default for
+.CW \[rs]*[ABSTRACT]
+includes font selection escape sequences to set the word in italics.
+.KE
+.
+.
+.KS
+.NH 2
+Glyphs for special characters
+.XS
+	Glyphs for special characters
+.XE
+.
+.
+.LP
+Some of the special character escape sequences used in this document
+are listed below.
+.
+The minus sign glyph can also be accessed by the shorthand
+.CW \[rs]\[mi] .
+.
+These and many others are documented in the
+.I groff_char (7)
+man page.
+.
+.
+.TS
+box center;
+Cb Lb Lb
+Lf(CR) L L .
+Input	Appearance	Description
+_
+\[rs][\-]	\[mi]	minus sign
+\[rs][\->]	\[->]	right arrow
+\[rs][aq]	\[aq]	neutral apostrophe
+\[rs][bu]	\[bu]	bullet
+\[rs][dq]	\[dq]	neutral double quote
+\[rs][dg]	\[dg]	dagger
+\[rs][em]	\[em]	em dash
+\[rs][ha]	\[ha]	circumflex accent (caret, hat)
+\[rs][lg]	\[lq]	left double quotation mark
+\[rs][rq]	\[rq]	right double quotation mark
+\[rs][rs]	\[rs]	reverse solidus (backslash)
+\[rs][sd]	\[sd]	seconds (double prime) mark
+\[rs][ti]	\[ti]	tilde
+.TE
+.KE
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+Page layout
+.XS
+Page layout
+.XE
+.LP
+.I ms 's
+default page layout arranges text
+in a single column
+with the page number
+between hyphens
+centered in a header
+on each page
+except the first,
+and produces no footers.
+.
+You can customize this arrangement.
+.
+.
+.NH 2
+Headers and footers
+.XS
+	Headers and footers
+.XE
+.
+.
+.LP
+There are multiple ways to produce headers and footers.
+.
+One is to define the strings
+.CW LH ,
+.CW CH ,
+and
+.CW RH
+to set the left,
+center,
+and right headers,
+respectively;
+and
+.CW LF ,
+.CW CF ,
+and
+.CW RF
+to set the left,
+center,
+and right footers.
+.
+This approach suffices for documents that do not distinguish odd- and
+even-numbered pages.
+.
+.
+.PP
+Another method is to call macros that set headers or footers for odd- or
+even-numbered pages.
+.
+Each such macro takes a delimited argument separating the left,
+center,
+and right header or footer texts from each other.
+.
+You can replace the neutral apostrophes (\[aq]) shown below with any
+character not appearing in the header or footer text.
+.
+These macros are Berkeley extensions.
+.
+.
+.TS
+box;
+lb lb
+lf(CR) lx.
+Macro	Description
+_
+\&.OH \[aq]\f[I]left\f[]\[aq]\f[I]center\f[]\[aq]\f[I]right\f[]\[aq]\
+	T{
+Set the left, center, and right headers on odd-numbered (recto) pages.
+T}
+\&.OF \[aq]\f[I]left\f[]\[aq]\f[I]center\f[]\[aq]\f[I]right\f[]\[aq]\
+	T{
+Set the left, center, and right footers on odd-numbered (recto) pages.
+T}
+\&.EH \[aq]\f[I]left\f[]\[aq]\f[I]center\f[]\[aq]\f[I]right\f[]\[aq]\
+	T{
+Set the left, center, and right headers on even-numbered (verso) pages.
+T}
+\&.EF \[aq]\f[I]left\f[]\[aq]\f[I]center\f[]\[aq]\f[I]right\f[]\[aq]\
+	T{
+Set the left, center, and right footers on even-numbered (verso) pages.
+T}
+.TE
+.
+.
+.PP
+With either method,
+a percent sign
+.B %
+in header or footer text is replaced by the current page number.
+.
+By default,
+.I ms
+places no header on a page numbered \[lq]1\[rq]
+(regardless of its number format).
+.
+.
+.TS
+box;
+lb lb
+lf(CR) lx.
+Macro	Description
+_
+\&.P1	T{
+Typeset the header even on page\~1.
+.
+To be effective,
+this macro must be called before the header trap is sprung on any page
+numbered \[lq]1\[rq];
+in practice,
+unless your page numbering is unusual,
+this means that you should call it early,
+before
+.CW .TL
+or any heading or paragraphing macro.
+.
+This is a Berkeley extension.
+T}
+.TE
+.
+.
+.PP
+For even greater flexibility,
+.I ms
+is designed to permit the redefinition of the macros that are called
+when the
+.I groff
+traps that ordinarily cause the headers and footers to be output are
+sprung.
+.
+.CW PT
+(\[lq]page trap\[rq])
+is called by
+.I ms
+when the header is to be written,
+and
+.CW BT
+(\[lq]bottom trap\[rq])
+when the footer is to be.
+.
+The
+.I groff
+page location trap that
+.I ms
+sets up to format the header also calls the
+(normally undefined)
+.CW HD
+macro after
+.CW .PT ;
+you can define
+.CW .HD
+if you need additional processing after setting the header
+(for example,
+to draw a line below it).
+.
+.\" Although undocumented in Tuthill's 4.2BSD ms.diffs paper...
+The
+.CW HD
+hook is a Berkeley extension.
+.
+Any such macros you (re)define must implement any desired specialization
+for odd-,
+even-,
+or first numbered pages.
+.
+.
+.KS
+.NH 2
+Tab stops
+.XS
+	Tab stops
+.XE
+.
+.
+.LP
+Use the
+.CW ta
+request to set tab stops as needed.
+.
+.
+.TS
+box;
+lb lb
+lf(CR) lx.
+Macro	Description
+_
+\&.TA	T{
+Reset the tab stops to the
+.I ms
+default
+(every 5 ens).
+.
+Redefine this macro to create a different set of default tab stops.
+T}
+.TE
+.KE
+.
+.
+.KS
+.NH 2
+Margins
+.XS
+	Margins
+.XE
+.
+.
+.LP
+Control margins using the registers summarized in the \[lq]Margins\[rq]
+portion of the table in section \[lq]Document control settings\[rq]
+above.
+.
+There is no setting for the right margin;
+the combination of page offset
+.CW \[rs]n[PO]
+and line length
+.CW \[rs]n[LL]
+determines it.
+.KE
+.
+.
+.KS
+.NH 2
+Multiple columns
+.XS
+	Multiple columns
+.XE
+.
+.
+.LP
+.I ms
+can set text in as many columns as reasonably fit on the page.
+.
+The following macros force a page break if a multi-column layout is
+active when they are called.
+.
+.CW \[rs]n[MINGW]
+is the default minimum gutter width;
+it is a GNU extension.
+.
+When multiple columns are in use,
+keeps
+and the
+.CW \%HORPHANS
+and
+.CW \%PORPHANS
+registers
+work with respect to column breaks instead of page breaks.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.1C	T{
+Arrange page text in a single column (the default).
+T}
+_
+\&.2C	T{
+Arrange page text in two columns.
+T}
+_
+\&.MC \f[R][\f[I]column-width\f[] [\f[I]gutter-width\f[]]]	T{
+Arrange page text in multiple columns.
+.
+If you specify no arguments,
+it is equivalent to the
+.CW 2C
+macro.
+.
+Otherwise,
+.I column-width
+is the width of each column and
+.I gutter-width
+is the minimum distance between columns.
+T}
+.TE
+.KE
+.
+.
+.\" ------------------------
+.NH 2
+Creating a table of contents
+.XS
+	Creating a table of contents
+.XE
+.LP
+Because
+.I roff
+formatters process their input in a single pass,
+material on page 50,
+for example,
+cannot influence what appears on page\~1\[em]this poses a challenge for
+a table of contents at its traditional location in front matter,
+if you wish to avoid manually maintaining it.
+.
+.I ms
+enables the collection of material to be presented in the table of
+contents as it appears,
+saving its page number along with it,
+and then emitting the collected contents on demand toward the end of the
+document.
+.
+The table of contents can then be resequenced to its desired location
+by physically rearranging the pages of a printed document,
+or as part of post-processing\[em]with a
+.I sed (1)
+script to reorder the pages in
+.I troff 's
+output,
+with
+.I pdfjam (1),
+or with
+.I gropdf (1)'s
+.B .pdfswitchtopage
+feature,
+for example.
+.
+.
+.PP
+Define an entry to appear in the table of contents by bracketing its
+text between calls to the
+.CW XS
+and
+.CW XE
+macros.
+.
+A typical application is to call them immediately after
+.CW NH
+or
+.CW SH
+and repeat the heading text within them.
+.
+The
+.CW XA
+macro,
+used within
+.CW .XS /\c
+.CW .XE
+pairs,
+supplements an entry\[em]for instance,
+when it requires multiple output lines,
+whether because a heading is too long to fit or because style dictates
+that page numbers not be repeated.
+.
+You may wish to indent the text thus wrapped to correspond to its
+heading depth;
+this can be done in the entry text by prefixing it with tabs or
+horizontal motion escape sequences,
+or by providing a second argument to the
+.CW XA
+macro.
+.
+.CW .XS
+and
+.CW .XA
+automatically associate the page number where they are called with the
+text following them,
+but they accept arguments to override this behavior.
+.
+At the end of the document,
+call
+.CW TC
+or
+.CW PX
+to emit the table of contents;
+.CW .TC
+resets the page number
+.B i "" to\~
+(Roman numeral one),
+and then calls
+.CW PX .
+.
+All of these macros are Berkeley extensions.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.XS \f[R][\f[I]page-number\f[]]	T{
+Begin,
+supplement,
+and end a table of contents entry.
+.
+Each entry is associated with
+.I page-number
+(otherwise the current page number);
+a
+.I page-number
+of
+.CW no
+prevents a leader and page number from being emitted for that entry.
+.
+Use of
+.CW .XA
+within
+.CW .XS /\c
+.CW .XE
+is optional;
+it can be repeated.
+.
+If
+.I indentation
+is present,
+a supplemental entry is indented by that amount;
+ens are assumed if no unit is indicated.
+.
+Text on input lines between
+.CW .XS
+and
+.CW .XE
+is stored for later recall by
+.CW .PX .
+T}
+\&.XA \f[R][\f[I]page-number\f[] [\f[I]indentation\f[]]]	\^
+\&.XE	\^
+_
+\&.PX \f[R][\f[]no\f[R]]	T{
+Switch to single-column layout.
+.
+Unless
+.CW no
+is specified,
+center and interpolate
+.CW \[rs]*[TOC]
+in bold and two points larger than the body text.
+.
+Emit the table of contents entries.
+T}
+_
+\&.TC \f[R][\f[]no\f[R]]	T{
+Set the page number to\~1,
+the page number format to lowercase Roman numerals,
+and call
+.CW PX
+(with a
+.CW no
+argument,
+if present).
+T}
+.TE
+.
+.
+.KS
+.PP
+Here's an example of typical
+.I ms
+table of contents preparation and
+its result.
+.
+We employ horizontal escape sequences
+.CW \[rs]h
+to indent the entries by sectioning depth.
+.
+.TS
+box center;
+L.
+T{
+.nf
+.CW
+\&.NH 1
+Introduction
+\&.XS
+Introduction
+\&.XE
+.R
+\&.\|.\|.
+.CW
+\&.NH 2
+Methodology
+\&.XS
+\[rs]h\[aq]2n\[aq]Methodology
+\&.XA no
+\[rs]h\[aq]4n\[aq]Fassbinder\[aq]s Approach
+\&.XA no
+\[rs]h\[aq]4n\[aq]Kahiu\[aq]s Approach
+\&.XE
+.R
+\&.\|.\|.
+.CW
+\&.NH 1
+Findings
+\&.XS
+Findings
+\&.XE
+.R
+\&.\|.\|.
+.CW
+\&.TC
+.fi
+T}
+.TE
+.KE
+.
+.nr SavedPageNumber \n%
+.nr SavedH1 \n[H1] \" groff ms internal name
+.nr SavedH2 \n[H2] \" groff ms internal name
+.nr % 1
+.rr H1
+.rr H2
+.als SavedTOC toc*div \" groff ms internal name
+.rm toc*div
+.di ThrowAway
+.NH 1
+Introduction
+.XS
+Introduction
+.XE
+.nr % 2
+.NH 2
+Methodology
+.XS
+\h'2n'Methodology
+.XA no
+\h'4n'Fassbinder's Approach
+.XA no
+\h'4n'Kahiu's Approach
+.XE
+.nr % 5
+.NH 1
+Findings
+.XS
+Findings
+.XE
+.br
+.di
+.\" We can't emit the TOC inside a B1/B2 box, so use lines instead.
+.R
+\l'\n[.l]u'
+.PX
+\l'\n[.l]u'
+.als toc*div SavedTOC
+.rm SavedTOC
+.nr % \n[SavedPageNumber]
+.nr H1 \n[SavedH1]
+.nr H2 \n[SavedH2]
+.rr SavedPageNumber
+.rr SavedH1
+.rr SavedH2
+.
+.
+.PP
+The remaining features in this subsection are GNU extensions.
+.
+.I "groff ms"
+obviates the need to repeat heading text after
+.CW XS
+calls.
+.
+Call
+.CW XN
+and
+.CW XH
+after
+.CW NH
+and
+.CW SH ,
+respectively.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.XN \f[I]heading-text	T{
+Format
+.I heading-text
+and create a corresponding table of contents entry;
+the indentation is computed from the depth of the preceding
+.CW NH
+call.
+T}
+\&.XH \f[I]depth heading-text	T{
+As
+.CW .XN ,
+but use
+.I depth
+to determine the indentation.
+T}
+.TE
+.
+.
+.KS
+.PP
+.I "groff ms"
+encourages customization of table of contents entry production.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.XN\-REPLACEMENT \f[I]heading-text	T{
+These hook macros implement
+.CW .XN
+and
+.CW .XH ,
+respectively.
+.
+They call
+.CW \%XN\-INIT
+and
+pass their
+.I heading-text
+arguments to
+.CW .\%XH\-UPDATE\-TOC .
+T}
+\&.XH\-REPLACEMENT \f[I]depth heading-text	\^
+\&.XH\-INIT	T{
+This hook macro does nothing by default.
+T}
+\&.XH\-UPDATE\-TOC\~ \f[I]depth heading-text	T{
+Bracket
+.I heading-text
+with
+.CW XS
+and
+.CW XE
+calls,
+indenting it by 2 ens per level of
+.I depth
+beyond the first.
+T}
+.TE
+.KE
+.
+.
+.LP
+.TS
+box center;
+L.
+T{
+.nf
+.CW
+\&.NH 1
+\&.XN Introduction
+.R
+\&.\|.\|.
+.CW
+\&.NH 2
+\&.XN Methodology
+\&.XH 3 \[dq]Fassbinder\[aq]s Approach\[dq]
+\&.XH 3 \[dq]Kahiu\[aq]s Approach\[dq]
+.R
+\&.\|.\|.
+.CW
+\&.NH 1
+\&.XN Findings
+.R
+\&.\|.\|.
+.CW
+\&.TC
+.fi
+T}
+.TE
+.
+.nr SavedPageNumber \n%
+.nr SavedH1 \n[H1] \" groff ms internal name
+.nr SavedH2 \n[H2] \" groff ms internal name
+.nr % 1
+.rr H1
+.rr H2
+.als SavedTOC toc*div \" groff ms internal name
+.rm toc*div
+.di ThrowAway
+.NH 1
+.XN Introduction
+.nr % 2
+.NH 2
+.XN Methodology
+.XH 3 "Fassbinder's Approach"
+.XH 3 "Kahiu's Approach"
+.nr % 5
+.NH 1
+.XN Findings
+.br
+.di
+.\" We can't emit the TOC inside a B1/B2 box, so use lines instead.
+.R
+\l'\n[.l]u'
+.PX
+\l'\n[.l]u'
+.als toc*div SavedTOC
+.rm SavedTOC
+.nr % \n[SavedPageNumber]
+.nr H1 \n[SavedH1]
+.nr H2 \n[SavedH2]
+.rr SavedPageNumber
+.rr SavedH1
+.rr SavedH2
+.
+.
+.PP
+To get the section number of the numbered headings into the table of
+contents entries,
+we might define
+.CW \%XN\-REPLACEMENT
+as follows.
+.
+(We obtain the heading depth from
+.I "groff ms" 's
+internal register
+.CW nh*hl .)
+.
+.
+.LP
+.TS
+box center;
+L.
+T{
+.nf
+.CW
+\&.de XN\-REPLACEMENT
+\&.XN\-INIT
+\&.XH\-UPDATE\-TOC \[rs]\[rs]n[nh*hl] \[rs]\[rs]$@
+\&\[rs]&\[rs]\[rs]*[SN] \[rs]\[rs]$*
+\&..
+T}
+.TE
+.
+.
+.PP
+You can change the style of the leader that bridges each table of
+contents entry with its page number;
+define the
+.CW TC\-LEADER
+special character by using the
+.CW char
+request.
+.
+A typical leader combines the dot glyph
+.CW .\& \[rq] \[lq]
+with a horizontal motion escape sequence to spread the dots.
+.
+The width of the page number field is stored in the
+.CW TC\-MARGIN
+register.
+.
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+Differences from AT&T
+.BI ms
+.XS
+Differences from AT&T
+.I ms
+.XE
+.LP
+The
+.I "groff ms"
+macros are an independent reimplementation,
+using no AT&T code.
+.
+Since they take advantage of the extended features of
+.I groff ,
+they cannot be used with AT&T
+.I troff .
+.
+.I "groff ms"
+supports features described above as Berkeley and Tenth Edition Research
+Unix extensions,
+and adds several of its own.
+.
+.
+.PP
+The internals of
+.I "groff ms"
+differ from those of AT&T
+.I ms .
+.
+Documents that depend upon implementation details of AT&T
+.I ms
+may not format properly with
+.I "groff ms" .
+.
+Such details include macros whose function was not documented in the
+AT&T
+.I ms
+manual [Lesk 1978].
+.\" TODO: Use refer(1).
+.\" XXX: We support RT anyway; maybe we should stop?
+.
+.
+.PP
+The error-handling policy of
+.I "groff ms"
+is to detect and report errors,
+rather than to ignore them silently.
+.
+.
+.PP
+Tenth Edition \" possibly 9th
+Research Unix supported
+.B P1 /
+.B P2
+macros to bracket code examples;
+.I "groff ms"
+does not.
+.
+.
+.PP
+.I "groff ms"
+does not work in GNU
+.I troff 's \" GNU
+AT&T compatibility mode.
+.
+If loaded when that mode is enabled,
+it aborts processing with a diagnostic message.
+.
+.
+.PP
+Multiple line spacing is not supported.
+.
+Use a larger vertical spacing instead.
+.
+.
+.PP
+.I "groff ms"
+uses the same header and footer defaults in both
+.CW nroff
+and
+.CW troff
+modes
+as AT&T
+.I ms
+does in
+.CW troff
+mode;
+AT&T's default in
+.CW nroff
+mode is to put the date,
+in U.S.\& traditional format
+(e.g.,
+\[lq]January 1, 2021\[rq]),
+in the center footer
+(the
+.CW CF
+string).
+.
+.
+.PP
+Many
+.I "groff ms"
+macros,
+including those for paragraphs,
+headings,
+and displays,
+cause a reset of formatting parameters,
+and may change the indentation;
+they do so not by incrementing or decrementing it,
+but by setting it absolutely.
+.
+This can cause problems for documents that define additional macros of
+their own that try to manipulate indentation.
+.
+Use
+.CW .RS
+and
+.CW .RE
+instead of the
+.CW in
+request.
+.
+.
+.PP
+AT&T
+.I ms
+interpreted the values of the registers
+.CW PS
+and
+.CW VS
+in points,
+and did not support the use of scaling units with them.
+.
+.I "groff ms"
+interprets values of the registers
+.CW PS ,
+.CW VS ,
+.CW FPS ,
+and
+.CW FVS
+equal to or larger than\~1,000
+(one thousand)
+as decimal fractions multiplied by\~1,000.\**
+.FS
+Register values are converted to and stored as basic units.
+.
+See \[lq]Measurements\[rq] in the
+.I groff
+Texinfo manual or in
+.I groff (7).
+.FE
+.
+This threshold makes use of a scaling unit with these parameters
+practical for high-resolution devices while preserving backward
+compatibility.
+.
+It also permits expression of non-integral type sizes.
+.
+For example,
+.CW "groff \-rPS=10.5p" \[rq] \[lq]
+at the shell prompt is equivalent to placing
+.CW ".nr PS 10.5p" \[rq] \[lq]
+at the beginning of the document.
+.
+.
+.PP
+AT&T
+.I ms 's
+.CW AU
+macro supported arguments used with some document types;
+.I "groff ms"
+does not.
+.
+.
+.PP
+Right-aligned displays are available.
+.
+The AT&T
+.I ms
+manual observes that \[lq]it is tempting to assume that
+.CW ".DS R"
+will right adjust lines,
+but it doesn't work\[rq].
+.
+In
+.I "groff ms" ,
+it does.
+.
+.
+.PP
+To make
+.I "groff ms"
+use the default page offset
+(which also specifies the left margin),
+the
+.B PO
+register must stay undefined until the first
+.I ms
+macro is called.
+.
+This implies that
+.B \[rs]n[PO]
+should not be used early in the document,
+unless it is changed also:
+accessing an undefined register automatically defines it.
+.
+.
+.PP
+.I "groff ms"
+supports the
+.CW PN
+register,
+but it is not necessary;
+you can access the page number via the usual
+.CW %
+register and invoke the
+.CW af
+request to assign a different format to it if desired.\**
+.FS
+If you redefine the
+.I ms
+.CW PT
+macro \" I wouldn't mention that, but Lesk 1978 encourages doing so. :-/
+and desire special treatment of certain page numbers
+(like
+.CW 1 \[rq]), \[lq]
+you may need to handle a non-Arabic page number format,
+as
+.I "groff ms" 's
+.CW .PT
+does;
+see the macro package source.
+.
+.I "groff ms"
+aliases the
+.CW PN
+register to
+.CW % .
+.FE
+.
+.
+.PP
+The AT&T
+.I ms
+manual documents registers
+.CW CW
+and
+.CW GW
+as setting the default column width and \[lq]intercolumn gap\[rq],
+respectively,
+and which applied when
+.CW .MC
+was called with fewer than two arguments.
+.
+.I "groff ms"
+instead treats
+.CW .MC
+without arguments as synonymous with
+.CW .2C ;
+there is thus no occasion for a default column width register.
+.
+Further,
+the
+.CW MINGW
+register
+and the second argument to
+.CW .MC
+specify a
+.I minimum
+space between columns,
+not the fixed gutter width of AT&T
+.I ms .
+.
+.
+.PP
+The AT&T
+.I ms
+manual did not document the
+.CW QI
+register;
+Berkeley and
+.I "groff ms"
+do.
+.
+.
+.PP
+The register
+.CW GS
+is set to\~1 by the
+.I "groff ms"
+macros,
+but is not used by the AT&T
+.I ms
+package.
+.
+Documents that need to determine whether they are being formatted with
+.I "groff ms"
+or another implementation should test this register.
+.
+.
+.\" XXX: We can't use a keep here because the wrong page number will be
+.\" recorded in the table of contents; see Savannah #63159.
+.\"KS
+.br
+.ne 6v
+.NH 2
+Unix Version\~7
+.BI ms
+macros not implemented by
+.BI "groff ms"
+.XS
+	Unix Version 7
+.I ms
+macros not implemented by
+.I "groff ms"
+.XE
+.LP
+Several macros described in the Unix Version\~7
+.I ms
+documentation are unimplemented by
+.I "groff ms"
+because they are specific to the requirements of documents produced
+internally by Bell Laboratories,
+some of which also require a glyph for the Bell System logo that
+.I groff
+does not support.
+.
+These macros implemented several document type formats
+(\c
+.CW EG , \" engineer's notes
+.CW IM , \" internal memorandum
+.CW MF , \" memorandum for file
+.CW MR , \" memorandum for record
+.CW TM , \" technical memorandum
+.CW TR ), \" technical report
+were meaningful only in conjunction with the use of certain document
+types
+(\c
+.CW AT , \" attachments
+.CW CS , \" cover sheet info for `TM` documents
+.CW CT , \" copies to
+.CW OK , \" "other keywords" for `TM` documents
+.CW SG ), \" signatures for `TM` documents
+stored the postal addresses of Bell Labs sites
+(\c
+.CW HO , \" Holmdel
+.CW IH , \" Naperville
+.CW MH , \" Murray Hill
+.CW PY , \" Piscataway
+.CW WH ), \" Whippany
+or lacked a stable definition over time
+(\c
+.CW UX ). \" Unix; on 1st use, add footnote identifying trademark owner
+.
+To compatibly render historical
+.I ms
+documents using these macros,
+we advise your documents to invoke the
+.CW rm
+request to remove any such macros it uses and then define replacements
+with an authentically typeset original at hand.\**
+.FS
+The removal beforehand is necessary because
+.I "groff ms"
+aliases these macros to a diagnostic macro,
+and you want to redefine the aliased name,
+not its target.
+.FE
+.
+For informal purposes,
+a simple definition of
+.CW UX
+should maintain the readability of the document's substance.
+.
+.
+.TS
+box center;
+lf(CR).
+\&.rm UX
+\&.ds UX Unix\[rs]"
+.TE
+.rs \" XXX: Work around Savannah #64005.
+.\"KE
+.
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+Legacy features
+.XS
+Legacy features
+.XE
+.
+.
+.LP
+.I "groff ms"
+retains some legacy features solely to support formatting of historical
+documents;
+contemporary ones should not use them because they can render poorly.
+.
+See
+.I groff_char (7)
+instead.
+.
+.
+.KS
+.NH 2
+AT&T
+.I ms
+accent mark strings
+.XS
+	AT&T
+.I ms
+accent mark strings
+.XE
+.LP
+AT&T
+.I ms
+defined
+accent mark strings as follows.
+.
+.
+.TS
+box center;
+Cb Lb
+Lf(CR) Lx.
+String	Description
+_
+\[rs]*[\[aq]]	Apply acute accent to subsequent glyph.
+\[rs]*[\[ga]]	Apply grave accent to subsequent glyph.
+\[rs]*[:]	Apply dieresis (umlaut) to subsequent glyph.
+\[rs]*[\[ha]]	Apply circumflex accent to subsequent glyph.
+\[rs]*[\[ti]]	Apply tilde accent to subsequent glyph.
+\[rs]*[C]	Apply caron to subsequent glyph.
+.\" \*v was an undocumented (in Lesk 1978-11-13) synonym for \*C.
+\[rs]*[,]	Apply cedilla to subsequent glyph.
+.TE
+.KE
+.
+.
+.NH 2
+Berkeley
+.I ms
+accent mark and glyph strings
+.XS
+	Berkeley
+.I ms
+accent mark and glyph strings
+.XE
+.LP
+Berkeley
+.I ms
+offered an
+.CW AM
+macro;
+calling it redefined the AT&T accent mark strings
+(except for
+.CW \[rs]*C ),
+applied them to the
+.I preceding
+glyph,
+and defined additional strings,
+some for spacing glyphs.
+.
+.
+.TS
+box;
+cb cb
+lf(CR) lx .
+Macro	Description
+_
+\&.AM	Enable alternative accent mark and glyph-producing strings.
+.TE
+.
+.
+.TS
+box center;
+Cb Lb
+Lf(CR) Lx.
+String	Description
+_
+\[rs]*[\[aq]]	Apply acute accent to preceding glyph.
+\[rs]*[\[ga]]	Apply grave accent to preceding glyph.
+\[rs]*[:]	Apply dieresis (umlaut) to preceding glyph.
+\[rs]*[\[ha]]	Apply circumflex accent to preceding glyph.
+\[rs]*[\[ti]]	Apply tilde accent to preceding glyph.
+\[rs]*[,]	Apply cedilla to preceding glyph.
+\[rs]*[/]	Apply stroke (slash) to preceding glyph.
+\[rs]*[v]	Apply caron to preceding glyph.
+\[rs]*[_]	Apply macron to preceding glyph.
+\[rs]*[.]	Apply underdot to preceding glyph.
+\[rs]*[o]	Apply ring accent to preceding glyph.
+_
+\[rs]*[?]	Interpolate inverted question mark.
+\[rs]*[!]	Interpolate inverted exclamation mark.
+\[rs]*[8]	Interpolate small letter sharp s.
+\[rs]*[q]	Interpolate small letter o with hook accent (ogonek).
+\[rs]*[3]	Interpolate small letter yogh.
+\[rs]*[d-]	Interpolate small letter eth.
+\[rs]*[D-]	Interpolate capital letter eth.
+\[rs]*[th]	Interpolate small letter thorn.
+\[rs]*[TH]	Interpolate capital letter thorn.
+\[rs]*[ae]	Interpolate small ae ligature.
+\[rs]*[AE]	Interpolate capital ae ligature.
+\[rs]*[oe]	Interpolate small oe ligature.
+\[rs]*[OE]	Interpolate capital oe ligature.
+.TE
+.rs \" XXX: Work around Savannah #64005.
+.
+.
+.\" ------------------------
+.if t \{\
+.  br
+.  bp
+.\}
+.NH 1
+Further reading
+.XS
+Further reading
+.XE
+.
+.
+.XP
+\[lq]Typing Documents on the Unix System:
+Using the \-ms Macros with Troff and Nroff\[rq];
+M.\& E.\& Lesk;
+November 13, 1978.
+.
+This document describes the
+.I ms
+supplied with AT&T Unix Version\~7.
+.
+.
+.XP
+\[lq]A Revised Version of \-ms\[rq];
+Bill Tuthill;
+August 1983.
+.
+The 4.2BSD release featured several extensions to
+.I ms ,
+most of which are recreated in
+.I "groff ms" .
+.
+(The exceptions are the
+.CW TM
+and
+.CW CT
+macros for setting a doctoral thesis in the format required by the
+contemporaneous degree-granting authorities of the University of
+California at Berkeley.)
+.
+.
+.XP
+\[lq]Using PDF boxes with
+.I groff
+and the
+.I ms
+macros\[rq];
+Deri James;
+March 2021.
+.
+.CW BOXSTART
+and
+.CW BOXSTOP
+macros are available via the
+.I sboxes
+extension package,
+enabling colored,
+bordered boxes when the
+.CW pdf
+output device is used.
+.
+This document is distributed with
+.I groff
+as the file
+.I msboxes.pdf .
+.
+.
+.LP
+This manual was composed using
+.I "groff ms" ;
+the curious may consult its source in the file
+.I ms.ms
+to see how its formatting was achieved.
+.\" ------------------------
+.TC
+.
+.
+.\" Local Variables:
+.\" fill-column: 72
+.\" mode: nroff
+.\" End:
+.\" vim: set filetype=groff textwidth=72: