I know that editing for typos or misspellings should be avoided in Stack Exchange sites. However, as this is a language site, I find dangerous to leave some mistakes in Spanish that could lead to learners to make them. For example, in this question Why is a comma used before a "y" in some cases? there is a mistake in this sentence:
Al exámen tengo que llevar lápiz, pluma y borrador.
Exámen has no tilde: examen. Actually, this is a common mistake among Spanish speakers and I don't think it's a good idea to leave it like this because a learner of Spanish could read it and start writing it like that (wrong).
What should we do in this cases? Edit the question/answer and leave a comment, or just leave a comment? I saw in other language forums that the community usually tells mistakes and I think we should do so.