Man pages matching name font::ttf::features::cvar in section 3pm:

Font::TTF::Features::Cvar.3pm.en	debian 10 / libfont-ttf-perl
Font::TTF::Features::Cvar.3pm.en	debian 11 / libfont-ttf-perl
Font::TTF::Features::Cvar.3pm.en	debian 12 / libfont-ttf-perl