Man pages matching name dpkg::control::fieldscore in section 3perl:

Dpkg::Control::FieldsCore.3perl.en	debian 10 / libdpkg-perl
Dpkg::Control::FieldsCore.3perl.en	debian 11 / libdpkg-perl
Dpkg::Control::FieldsCore.3perl.en	debian 12 / libdpkg-perl