Feature Request: in-code Bookmarks

In many instances, I need to work with PHP files that are massively overbloated. I think plenty of plenty of people here can feel what that means. It would be nice to be able to right click the left hand margin and add bookmarks or favourites or stars or whatever you want to call them. I often find myself having to compare snippets of code or refer back to object definitions and simply being able to click a couple of shortcuts would be a massive time saver.