A Service Class Specification defines a group of one or more SOP Classes related to a specific function that is to be accomplished by communicating Application Entities. A Service Class Specification also defines rules that allow implementations to state some pre-defined level of conformance to one or more SOP Classes. Applications may conform to SOP Classes as either or both a Service Class User (SCU) or Service Class Provider (SCP).

Service Class Specifications are defined in PS3.4.