Man pages matching name marc::spec::comparisonstring in section 3pm:

MARC::Spec::Comparisonstring.3pm.en	debian 10 / libmarc-spec-perl
MARC::Spec::Comparisonstring.3pm.en	debian 11 / libmarc-spec-perl
MARC::Spec::Comparisonstring.3pm.en	debian 12 / libmarc-spec-perl