Man pages matching name pmnotifyerr in section 3:

pmNotifyErr.3.en	debian 10 / libpcp3-dev
pmnotifyerr.3.en	debian 10 / libpcp3-dev
pmNotifyErr.3.en	debian 11 / libpcp3-dev
pmNotifyErr.3.en	debian 12 / libpcp3-dev