If an AutoFill Keyword Set allows multiple sets to have the same primary value, then the HL7 AutoFill Keyword Set message action may need to use a secondary value to distinguish between two sets that have the same primary.
For example, if the Medical Record Number (MRN) is the primary Keyword Type, and MRNs are not unique, then you may need to uniquely identify each MRN by using the Assigning Authority as a secondary value.
To designate a Keyword Type for secondary searching: