The quick and dirty way to select classification codes for your paper. Now you can safely submit to ArXiv, DROPS Dagstuhl, or any other publisher that requires such codes.
Use the search input to filter using fuzzy matching the classification codes of your choice (ACM 1998, ACM 2012, or MSC 2010). Click on the results to add them to your selection. You can then export them in different formats, by clicking the "Export Selection" button which copies the relevant code to your clipboard.