Labels can be useful for organizing information on your site and making it more discoverable and transparent for your audience. They show up and read an article about a particular topic and if they like it and it has a good label, they can click on the label to find other articles on the same subject which may be of interest to them. But sometimes when I reorganize a site, I don't like the labels I have been using. Then, when you go to pick a label, Blogger gives you a drop down list of all the labels you have ever used and it includes labels only found on draft posts. So if you have done a major reorganization and don't want those labels cluttering up your drop down list, you have to go back through all your draft posts and either delete or update all appearances of any labels you would like to permanently retire. That's the only way I know to get them out of your list. It's annoying, but it usually only takes a few minutes. It can be well worth the reductio...