If you have a physical media collection for movies, TV shows, games, music, or something else, you’ve probably wondered “do I already have this?” while shopping. There’s an easy way to solve this problem: make a simple list.

There are many apps and services intended for tracking your collection of movies, games, music, and other media across digital and physical formats. Those are useful tools, especially the ones with the ability to add extra metadata, but they aren’t strictly necessary. If you just want to know what you already own, so you can quickly check you aren’t about to buy the same movie or game again, you can go for a more basic solution.