Man pages matching name setprotoent in section 3:

setprotoent.3.en	debian 10 / manpages-dev
setprotoent.3.es	debian 10 / manpages-es
setprotoent.3.ja	debian 10 / manpages-ja-dev
setprotoent.3.pl	debian 10 / manpages-pl-dev
setprotoent.3.en	debian 11 / manpages-dev
setprotoent.3.fr	debian 11 / manpages-fr-dev
setprotoent.3.ja	debian 11 / manpages-ja-dev
setprotoent.3.pl	debian 11 / manpages-pl-dev
setprotoent.3.en	debian 12 / manpages-dev
setprotoent.3.es	debian 12 / manpages-es-dev
setprotoent.3.ja	debian 12 / manpages-ja-dev
setprotoent.3.pl	debian 12 / manpages-pl-dev