6.5 Syntax and semantics of messages
The syntax and semantics of the messages defined in this standard are provided in an XSD file. The XSD is an integral part of this standard and can be accessed here. This includes the allowed value sets as specified in Clause 6.6.
A structural feature of the XSD is the cardinality for each field. These are:
1-n means one or more;
1 means exactly one;
0-1 means none or one; and
0-n means none to multiple.