Should good answers to a question influence which tags are appropriate for that question thread? In other words, are the tags dictated only by the content of the question, or by the content of the question plus the content of the good answer(s)?
Sometimes the poser of a question doesn't understand the various concepts involved (or chooses not to discuss his knowledge of it), so the question may directly relate to several concepts that are not mentioned. A good answer might clarify the question at hand and introduce a couple relevant concepts.
For example, a question may touch on the idea of a One Time Pad, and the OP will make no mention of it, but the accepted answer mentions and outlines the relevance of the OTP to the question. Or a question may ask about some general notion of the security of a block cipher and the best answer outlines how the semantic security definition addresses their question. If the original questions didn't mention or tag OTP and semantic security (respectively), should they?
I would think there is a general SE policy on this, but I didn't see anything. (And apologies if this is covered somewhere I should have been able to find it.)