Being an erogenous zone between the genitalia and the anus, should it be considered part of the genitalia like the anus is and thus always be tagged explicit when not covered?
Example: https://e621.net/post/show/1510411/

Should it not be tagged for featureless crotches since they are devoid of detail?
Example: https://e621.net/post/show/1279262/

Should there be a separate tag for when it is a bulge under clothing?
Example: https://e621.net/post/show/1097929/

Where does perineum end and backsack begin?
Example: https://e621.net/post/show/1067073/

I think that's enough questions to start off with, let the discussion begin!