The Matching Key Attributes are Keys, which select Query items to be included in a requested Query.
A Substance Administration Query Service SCP shall support matching based on values of all Required Matching Key Attributes of the C-FIND request.
In the Substance Administration Query Information Model, a set of Attributes may be defined as Optional Matching Key Attributes. Optional Matching Key Attributes contained in the Identifier of a C-FIND request may induce two different types of behavior depending on support for matching by the SCP. If the SCP
— does not support matching on the Optional Matching Key Attribute, then the Optional Matching Key Attribute shall be ignored for matching but shall be processed in the same manner as a Return Key Attribute.
— supports matching of the Optional Matching Key Attribute, then the Optional Matching Key Attribute shall be processed in the same manner as a Required Matching Key.
Notes: 1. The Conformance Statement of the SCP lists the Optional Matching Key Attributes that are supported for matching.
2. An SCU can not expect the SCP to support a match on an Optional Matching Key.