To expand on chip's point, perldoc has the handy '-m' switch which lists the entire module as found by perl in @INC.

$ perldoc -m HTTPD::RealmManager # paged listing follows
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Look at @EXPORT and @EXPORT_OK near the top for names. If your $ENV{'PAGER'} supports searching, you can go directly to the definition you want.

su

After Compline,
Zaxo