Media Auxiliary Memory or Medium Auxiliary Memory (MAM) refers to a chip embedded into a digital media device (usually a tape cartridge) that stores a small amount of data or metadata that a computer can read without having to read the actual tape.
MAMs can be used by the tape driver to increase efficiency, or by custom software to store & retrieve custom data.
Some examples of MAM's are Cartridge Memory (HP/Seagate/IBM LTO) and MIC (Sony AIT).
References
Media Auxiliary Memory Wikipedia(Text) CC BY-SA