When editing a post, there’s a nifty (add edit reason) link to click and then type in a line to explain why you are editing it. It’s important and useful, even more so now that edit notifications can be browsed all in one place via your profile page.
Often I forget to add the edit reason, so suggest this exact same functionality be added to the history view, so that when you are browsing through the history you can click (add edit reason) and type in the explanation of the edit.