I have found few old posts in P SE in which asked questions are not clear. So no one has answered it or it has ambiguous answers in it. Is it possible for someone else other than the author to modify the contents of the post and re post it, so it can be useful to others. The reason I am asking this is- I don't think it is considered to be a good practice to change the content of the post without the permission of the author. But with little modification of the corresponding post it would be helpful to others.
I am not talking about edits for punctuation or grammar etc.. I am talking about the main content of the post. By asking 'Is it possible' I don't mean 'Is it possible?' I am asking the validity according to the etiquette.