It depends, but I tend to do so since: - Simple typos or a dropped word can significantly alter the meaning of a post. I once wrote a post where I said one thi

It depends, but I tend to do so since: - Simple typos or a dropped word can significantly alter the meaning of a post. I once wrote a post where I said one thing, yet a single sentence appeared to say the exact opposite (either due to a typo or dropped word). I doubt that many people noticed it or, if they did, they would recognize the error for what it is. Still, you never know. - Something similar can be said of grammatical errors. Grammar conveys meaning and ambiguous/incorrect grammar leads to ambiguous/incorrect meaning. Again, edits will alter the meaning of what is said even if most people would have interpreted what you said as what you meant. I have noticed some edits as an acknowledgement to someone who noticed an obvious error, that is just a courteous thank-you. There's nothing wrong with that. Also, quoting is common here. Editing the original without noting the edit leads to confusion as to who made the change. Usually it won't matter, but it is good to point out the edits in case it does end up being significant.