Just because HL7 only says there is one type of HL7 lab result it does not mean you cannot divide lab results into several different categories. The VMD file's message identity can categorize messages based on any segment, not just the MSH segment. You can identify messages by the contents of any field in the message such as:

• The sending application and/or vendor;
• The lab result type (field in the first OBX segment); or
• Room number.

	You can use any criteria you can think of to filter messages. To learn more about filtering messages, see Filtering Messages Using the Message Identity.