HL7 Version 2.x Messaging Standard
The HL7 version 2 messaging standard defines a series of electronic messages to support administrative, logistical, financial, and clinical processes. The standard has undergone frequent updates and has resulted in a series of ANSI approved versions, collectively know as version 2.x.
The HL7 version 2.x messaging standard uses two types of encoding:
Standard encoding. The standard encoding is a textual, non-XML encoding syntax based on delimiters, also known as encoding rule-7 format (ER7).
HL7 XML encoding. The HL7 XML encoding is defined by XML encoding rules that represent HL7 message structures, components and fields as XML elements.
For examples of HL7 version 2.x messages of the two encoding types, see
Example: HL7 ER7-Encoded Message and
Example: HL7 XML-Encoded Message.