Tagging Spoilers After Posting

Idea for a feature that adds an option in the right click menu to set images to spoilers AFTER the user has posted it.

This could be useful for when you accidentally didn't mark it as a spoiler and now you could fix that without having to re-post.

Also useful when a user posts something that's a spoiler or should be hidden, and refuses to re-post it. A moderator can set it without needing them to do so.

I'm unsure how this could be implemented for text spoilers however, maybe by selecting text and right clicking, or turning the entire message to a spoiler.