(I can't formally suggest this since finger is already aliased to fingers)

fingers → invalid_tag
finger → invalid_tag

fingers is a generic tag.
It's possible images exist that have a focus on the finger, but the same might be true for a tag like hand or arm which have also been aliased to invalid_tag.

Either way, for generally referring to fingers, it's way undertagged and probably too generic, and for a focus on fingers, it seems astronomically mistagged.

It is worth mentioning that the wiki for finger currently lists the_finger and fingering, however I don't think it's very viable to use fingers to describe both those things. It seems contrived.

Overall, I haven't really been able to find out what the tag is used for other than the generic body part (which according to the tagging checklist is a bad thing to do).

I'm surprised at the amount of posts that are tagged with "fingers", and I get the feeling that I'm missing something, but since this tag seems to me like it should be invalid, I'd rather create a thread for it and be wrong than let it fly under the radar and be right.