An Identifier in a C-FIND request shall contain
— Key Attributes values to be matched against the values of Attributes specified in that SOP Class.
— Conditionally, the Attribute Specific Character Set (0008,0005). This Attribute shall be included if expanded or replacement character sets may be used in any of the Attributes in the Request Identifier. It shall not be included otherwise.
Note: This means that Specific Character Set (0008,0005) is included if the SCU supports expanded or replacement character sets in the context of this service. It will not be included if expanded or replacement character sets are not supported by the SCU.
The Key Attributes and values allowable for the query shall be defined in the SOP Class definition for the corresponding Substance Administration Query Information Model.