Man pages matching name xcb_glx_get_clip_plane in section 3:

xcb_glx_get_clip_plane.3.en	debian 10 / libxcb-doc
xcb_glx_get_clip_plane.3.en	debian 11 / libxcb-doc
xcb_glx_get_clip_plane.3.en	debian 12 / libxcb-doc