Man pages matching name declare::constraints::simple::library::referencial in section 3pm:

Declare::Constraints::Simple::Library::Referencial.3pm.en	debian 10 / libdeclare-constraints-simple-perl
Declare::Constraints::Simple::Library::Referencial.3pm.en	debian 11 / libdeclare-constraints-simple-perl
Declare::Constraints::Simple::Library::Referencial.3pm.en	debian 12 / libdeclare-constraints-simple-perl