Unnecessary comma.

Existing Wording:

The type may be a general category, such as a Condition, Procedure, or Encounter, or a more specific instance such as an ImagingProcedure, or a LaboratoryTest. The data model defines the available types that may be referenced by a retrieve.

Proposed Wording:

The type may be a general category, such as a Condition, Procedure, or Encounter, or a more specific instance such as an ImagingProcedure or a LaboratoryTest. The data model defines the available types that may be referenced by a retrieve.