Man pages matching name uuid_is_null in section 3:

uuid_is_null.3.ja	debian 10 / manpages-ja-dev
uuid_is_null.3.en	debian 10 / uuid-dev
uuid_is_null.3.de	debian 11 / manpages-de-dev
uuid_is_null.3.fr	debian 11 / manpages-fr-dev
uuid_is_null.3.ja	debian 11 / manpages-ja-dev
uuid_is_null.3.en	debian 11 / uuid-dev
uuid_is_null.3.de	debian 12 / manpages-de-dev
uuid_is_null.3.fr	debian 12 / manpages-fr-dev
uuid_is_null.3.ja	debian 12 / manpages-ja-dev
uuid_is_null.3.en	debian 12 / uuid-dev