A type of data that can be defined and validated via a ruleset or schema. Examples include eXtensible Markup Language (XML), JavaScript Object Notation (JSON), Key-Length-Value (KLV), United States Message Text Format (USMTF), Tactical Digital Information Link-J (TADIL-J), and Variable Message Format (VMF). Fixed format data can be textual or binary. Fixed format data is primarily used for machine-to-machine messaging and is generally designed to be efficiently processed by software.
Sources:
CNSSI 4009-2022