[quickbook 1.7]
[article Footnotes]

[section:first First Section]

Some[footnote First footnote] normal[footnote Second footnote] footnotes[footnote Third footnote].

[endsect]

[section:second Second Section]

Some'''<footnote id="f1"><para>Boostbook footnote</para></footnote>'''
boostbook'''<footnote><para>Footnote without id</para></footnote>'''
footnotes'''<footnote><para>Another footnote without an id</para></footnote>'''.

[endsect]