The following basic record types are well developed and in use in ITS, and the SDO FADDs are made up almost entirely of these four types:
Data Element A simple structure made up of a single primitive element (integer, string, etc.) which forms part of a data dictionary and which may be used in (inside) data frames and other structures consisting of valid ASN and XML (as a type, not as an element).
Data Frame A complex structure made up of a combination of primitive elements (int, string, etc.) and/or other complex structures which forms part of a data dictionary and which may be used in data frame and other structures. Consisting of valid ASN and XML (as a type, not as an element).
Message A complex structure made up of a combination of primitive elements (int, string, etc.) and/or other complex structures which forms part of a data dictionary and which may be used in data frame and other structures. This complex structure can be exchanged between parties to effect a functional requirement. Consisting of valid ASN and XML (both an element and a type).
Dialog A mapping to one or more messages in a service endpoint performing some form of operation, typically expressed in WSDL.