I see a lot of "EDIT" in a question or answer (I use it too), to refine it after some interactions with others, or when there's a new solution (full or partial).
here is an example which uses a "EDITED =======" notation in the answer, but mostly people use Heading Size 1 for the word "Edit" (also in that example - first answer).
IMHO it could be useful to have a standard EDIT notation.
Also, knowing what kind of EDIT could be nice (is it a final solution? is it a refinement?, also: filter by edited, etc)
More examples to consider:
- camickr's "see above edit" comment to his answer's edit
- An UPDATE notation used both in question and answer and another UPDATE in an answer
- An EDIT in a question with some amount of traction (39 answers, ~100 votes for question and top answers)
And while looking around for examples, I see these kind of edits everywhere. It may be abusive or at least bad taste, but if users are using it so much, why not formalize it in a way that makes SO better?