Mnemonics are used, among other things, in assembly to translate confusing columns of numbers into simple memorable machine commands. Mnemonics that are as short and easy to remember as possible are chosen for this purpose. Simple examples are "add" for adding, "mov" for moving or "cli" for clear interrupt. Mnemonics are freely chosen short names, which are defined only for a certain processor family or a special system. To be able to use mnemonics in programming, they must be explained in a command list.