Magic number (programming)
In computer programming, a magic number or file signature is a numeric literal in source code that has a special, particular meaning that is less than clear to the reader. Also in computing, but not limited to programming, the term is used for a number that identifies a particular concept but without additional knowledge its meaning is less than clear. For example, some file formats are identified by an embedded magic number in the file ). Also, a number that is relatively uniquely associated with a particular concept, such as a universally unique identifier, might be classified as a magic number.