Man pages matching name pmdamain in section 3:

pmdaMain.3.en	debian 10 / libpcp-pmda3-dev
pmdamain.3.en	debian 10 / libpcp-pmda3-dev
pmdaMain.3.en	debian 11 / libpcp-pmda3-dev
pmdaMain.3.en	debian 12 / libpcp-pmda3-dev