The data types in this section are listed in alphabetical order.
The data type examples in this Standard are given using the standard HL7 encoding rules, with the delimiter values from Figure 2-1 of Chapter 2, "Control", section 2.5.4, "Message delimiters".
Note: These message construction rules define the standard HL7 encoding rules, creating variable length delimited messages. Although only one set of encoding rules has been defined as a standard since HL7 Version 2.3, other encoding rules are possible (but since they are non-standard, they may only be used by a site-specific agreement). In this chapter, square brackets, "[" and "]", are used to specify optional parts of a string. For instance, the format of a date field is "YYYY[MM[DD]]" which denotes that the field may contain four, six, or eight characters respectively. The characters may further constrain the possible contents of the string - this will be documented at the point of use.