So you have a ton of categories and there are a lot of child categories at the list and the post editor has become unruly? In order to change a posts' category or to add it to a new one the list is unmanageable. Here is a jQuery code snippet that you can use to make the categories collapsable. It removes the label functionality. You cannot click on the name to select the item's checkbox, but it now allows you to click on the name to expand the categories.