man.links.are.numbered — Number links?
If the value of man.links.are.numbered is
non-zero (the default), then for each non-empty[1] link:
a number (in square brackets) is displayed inline before the rendered contents of the link
the URL for the link is included in a numbered list of links that is generated at the end of each man page; the number for each links corresponds to the inline number for the link with which it is associated
The default heading for the list of links is
REFERENCES. To output a different heading, set a value
for the man.links.section.heading
parameter.
The link list is also displayed (but without numbers) if the
value of man.links.list.enabled is
non-zero.
If the value of man.links.are.numbered is
zero, numbering of links is suppressed; only the link contents are
displayed inline.
If you are thinking about disabling link numbering by setting
the value of man.links.are.numbered to zero,
before you do so, first take some time to carefully
consider the information needs and experiences of your users. The
square-bracketed numbers displayed inline before links may seem
obstrusive and aesthetically unpleasing[2],
but in a text-only output format, the numbered-links/link-listing
mechanism is the only practical way of associating inline text with
URLs.
Also, users of “text based” browsers such as
lynx will already be accustomed to seeing inline
numbers for links. And various "man to html" applications, such as
the widely used man2html (VH-Man2html)
application, can automatically turn URLs into "real" HTML hyperlinks
in output. So leaving man.links.are.numbered
at its default (non-zero) value ensures that no link information is
lost in your man-page output. It just gets
“rearranged”.
The handling of empty links is not affected by this parameter. Empty links are handled simply by displaying their URLs inline. Empty links are never auto-numbered.
Currently, this parameter only affects output for
ulinks.
If you disable link numbering, you should probably also set
man.links.are.underlined to zero (to disable
link underlining).
[1] A “non-empty” link is one that looks like this:
<ulink url="http://docbook.sf.net/snapshot/xsl/doc/manpages/">manpages</ulink>an “empty link” is on that looks like this:
<ulink url="http://docbook.sf.net/snapshot/xsl/doc/manpages/"/>
[2] You might
think that it would be better to just display URLs for non-empty
links inline, after their content, rather than displaying
square-bracketed numbers all over the place. But it's not better. In
fact, it's not even practical, because many (most) URLs for links
are too long to be displayed inline. They end up overflowing the
right margin. You can set a non-zero value for
man.break.after.slash parameter to deal with
that, but it could be argued that what you end up with is at least
as ugly, and definitely more obstrusive, then having short
square-bracketed numbers displayed inline.