It strikes me as a breach of etiquette to edit or delete another person's comment. Where can I find the guidelines on, or discussions of that topic?
Only moderators and the commenter have the ability to edit or delete comments, and commenters can only edit within a short timeframe. I added the comments tag to this question. You can find posts related to these activities within that tag. Please feel free to post another Meta question if you have something more specific that you can't find an answer for.