S means the symbol is not used outside its own file.
It could either be completely unused or used locally. It might be appropriate to make it
static.
Z means the symbol is not used outside its own file,
and it's not visible to the outside of the library or daemon (i.e. ELF hidden linkage.)
It could still be completely unused, or used within the library. It might be appropriate to make it
static.
L means the symbol is used from other files in the library,
but not from outside. It might be appropriate to make it DSO_LOCAL.
A means the symbol is used from some other file, most likely a
loadable module. Note this is only flagged for symbols in executable files, not libraries.
T are normal functions ("program Text")
B (BSS), C (Common), D (Data)
are various types of writable global variables
R are read-only global variables ("Rodata")
{%- for subdir, subreport in dirgroups.items()|sort %}