Man pages matching name ref::util::xs in section 3pm:

Ref::Util::XS.3pm.en	debian 10 / libref-util-xs-perl
Ref::Util::XS.3pm.en	debian 11 / libref-util-xs-perl
Ref::Util::XS.3pm.en	debian 12 / libref-util-xs-perl