Mature Standard – HL7V2.x emerged as a mature stable standard in healthcare informatics after the specifications went through series of review iterations and modifications to cater to the needs of market. The HL7V2.x specifications are currently available and ready for use and easily implementable. A large number of existing applications are HL7V2.x conformant.
International Standard – HL7 has international affiliates in around 28 countries covering all major countries. It has emerged as the dominant clinical information standard in these markets. Majority of the HL7V2.x specifications including HL7V2.3/2.4 have been classified as ANSI accredited standards. HL7V2.4 is now being proposed as ISO standard. Apart from this some countries such as Germany have legislations that stipulate use of HL7V2.x.
Backward Compatibility - The biggest advantage of HL7V2.x is the ability of different versions of HL7V2.x to interoperate with one another. The rules for compatibility between different versions (e.g. V2.3.1, V2.4 and V2.5) have been documented in the specifications. These rules describe the transmission and receipt of messages and converting their contents to data values with full backward compatibility between all HL7V2.x versions.
Optionality - The use of optionality in HL7V2.x messages is helpful in gaining consensus and documenting compact specification. If a data field is declared optional within a segment then the segment can be re-used in different messages without defining a new segment which requires similar data fields. However there is a wide misuse of this optimality which will be discussed in next section.
Message Size: The chief virtue of HL7V2.x message specification is that its syntax is quite compact and hence the size of the message is minimal. This brings a huge benefit to the economy of bandwidth