Machine Readable Zone – MRZ Lines / Code is a three-letter abbreviation of “Machine Readable Zone”, found at most travel passports and some driver’s licenses and ID cards.
Standardized by the ICAO Document 9303 (endorsed by the International Organization for Standardization and the International Electrotechnical Commission as ISO/IEC 7501-1).
The MRZ code includes the documents owner’s personal data sat and forgery detection numbers called “Checksum”.
Ref.: https://en.wikipedia.org/wiki/Machine-readable_passport