Man pages matching name polygon_z_normal in section 3alleg4:

polygon_z_normal.3alleg4.en	debian 10 / allegro4-doc
polygon_z_normal.3alleg4.en	debian 11 / allegro4-doc
polygon_z_normal.3alleg4.en	debian 12 / allegro4-doc
polygon_z_normal.3alleg4.en	debian 13 / allegro4-doc