|1||Coded Value for HL7-Defined Tables||SHALL||=||[0..1]||[1..]||15|
Minimum Length: ≥ 1- Varies - dependent on length of shortest code in code set.
Maximum Length: Varies - dependent on length of longest code in code set.
Note: The Vocabulary TC is the steward of the ID data type.
Definition: The value of such a field follows the formatting rules for an ST field except that it is drawn from a table of legal values. There shall be an HL7 table number associated with ID data types. An example of an ID field is OBR-25 Result Status. This data type should be used only for HL7 tables (see Chapter 2C, section 2.C.1.2, "HL7 Tables"). The reverse is not true, since in some circumstances it is more appropriate to use the CNE or CWE data type for HL7 tables.
The minimum and maximum lengths are specified in the context in which the ID data type is used. The longest HL7 defined legal value is 15 characters, but there are a few circumstances where the legal values are taken from code systems defined by other bodies (such as IANA mime types). In these cases, a different conformance length may be specified where the ID data type is used. It is never acceptable to truncate an ID value.