Your home country is in the middle of an economic crisis and you are forced to sell your music collection to make ends meet. For reasons that only the government can explain they have allowed to to keep one Best Of/Greatest Hits compilation per artist. You can have as many compilations as you want, but only one per arist. For example, you’re allowed to have only one of the following albums by The Beatles – 1, The Red Album, The Blue Album, Past Masters. You have to choose between 40 Licks and Hot Rocks by the Stones.