Hello,

the conversation in
https://salsa.debian.org/freexian-team/debusine/-/merge_requests/300#note_434002
led me to realize that as a simple lintian user reading the manual page,
you can't discover the existence of classification tags and you can't
figure out the syntax to enable the display of those tags.

Please improve the manual page to explain what classification tags are,
that they are considered like normal tags with a priority lower than
everything else and that you can enable them with "--display-level
+=classification".

BTW in general, the whole explanation about --display-level is pretty
confusing, it's not clear to me what "S|C|S/C" is supposed to mean for
instance. And there's no global sorted list of usable severity so
it's hard to predict the result of --display-level '>=classification'.

Cheers,