I propose to delete the tag. There are other tags that can be used in its place, as appropriate: proof-strategy, contest-math, puzzle, or recreational-mathematics.
One can imagine that the tag was meant for abstract problem solving techniques in the style of How to Solve It by Pólya. But it's hard to come up with many SE-suitable questions along ...
Magazine article by James Sommers :
discussion on MO:
It would great to have solutions to as many book problems as possible on MSE, indexed as searchably as possible ---- but self-answered questions by learners are not the best way to upload that content. People solving exercises as a way of learning the material will (on average) produce lower-quality solutions than people with more knowledge.
For learners ...
One possible way would be to work like this:
Start writing list of posts corresponding to the exercises in some editor of your choice.
For each exercise either find already existing post on this problem or create a new question if needed.
You can share the link to this list in your profile (or elsewhere).
For example, you could create a text containing ...