Man pages matching name bio::seq::richseqi in section 3pm:

Bio::Seq::RichSeqI.3pm.en	debian 10 / libbio-perl-perl
Bio::Seq::RichSeqI.3pm.en	debian 11 / libbio-perl-perl
Bio::Seq::RichSeqI.3pm.en	debian 12 / libbio-perl-perl