Man pages matching name geo::coordinates::osgb in section 3pm:

Geo::Coordinates::OSGB.3pm.en	debian 10 / libgeo-coordinates-osgb-perl
Geo::Coordinates::OSGB.3pm.en	debian 11 / libgeo-coordinates-osgb-perl
Geo::Coordinates::OSGB.3pm.en	debian 12 / libgeo-coordinates-osgb-perl