What are the mysterious Post Replacements? Who can use it and in which cases? I can't find any help topic on this. The link to it is also on every post page under the "History" section.
As I guess this is something that allows to replace the file of the post. But if it's true, then why old inferior posts are still being deleted, when they could have just be replaced? Such feature would be useful, because I think it's better to replace the post instead of deleting it, as it would preserve score, comments, tag history, avatars, sets, etc. At the moment the post replacement feature looks very underused.