Man pages matching name markdent::dialect::theory::spanparser in section 3pm:

Markdent::Dialect::Theory::SpanParser.3pm.en	debian 10 / libmarkdent-perl
Markdent::Dialect::Theory::SpanParser.3pm.en	debian 11 / libmarkdent-perl
Markdent::Dialect::Theory::SpanParser.3pm.en	debian 12 / libmarkdent-perl