Sounds like it would be better suited for the late, lamented Wiki.
I wonder if we're ever going to get that back.
Until then, I think there are too many functions to add a sub-category for each one (and new functions are added with each version). I would prefer a Subject heading that included the function and some prefix text to aid the Search function, say... "EXPLAIN <3D function name> USAGE", followed by a descriptor for the basic problem.
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