Missing documentation regarding the anatomical definitions of the 468 face landmarks

[fangq]

my student and I are working on a robust registration between face-mesh with other head/brain-landmarks used for neuroimaging, specifically, the 10-20 system for EEG.

the comments in a previous issue (#1615) seem to give a good picture how these face landmarks are numbered, but I still don't see a rigorous definition on where these key points are supposed to be from a face-feature perspective, for example, where is landmark 10 is supposed to be located? middle of the forehead? is there a standard or document where I can find face landmark's "actual" ~~geometric~~ anatomical definitions?

thanks