Man pages matching name naco_img_twflat in section 7:

naco_img_twflat.7.en	debian 10 / cpl-plugin-naco-doc
naco_img_twflat.7.en	debian 11 / cpl-plugin-naco-doc
naco_img_twflat.7.en	debian 12 / cpl-plugin-naco-doc