The AFD has three technical meta-entities in which information about the message can be stored. The commonFunctional entity covers all information about the content of the message. This is typically domain-specific information, while the commonTechnical entity primarily provides technical message-related meta-data. The third technical entity is specifically meant for error messages. Normally, content from technical entities is not stored in local databases, but only used for the exchange of data.
All technical entities are explained in more detail in the next sections.