- Constrain search and data entry

- Define alternative navigation hierarchies

- Specify order of display of a group of          

  concepts or descriptions 

•  Simple type reference set

• Ordered reference set

• Query specification reference set

- Linkage between SNOMED CT components   and knowledge resources 

- Linkage between SNOMED CT components   and decision support rules to trigger alerts. 

• Simple map reference set

• Complex and Extended map  reference set

• Annotation reference set

- Specify mappings between SNOMED CT      components and other coding systems used  for reporting, billing etc. 

• Simple type reference set

• Simple map reference set

• Complex and Extended map reference set

- Linkage between elements in  communication messages and SNOMED CT  components 

• Simple type reference set

• Simple map reference set

• Complex and Extended map reference set

- Indicate which descriptions that are    acceptable or preferred in a particular  language or dialect.

• Language reference set

• Simple type reference set 

- Specify intensional reference set definitions  to be embedded in specific parts of the EHR

- Linking components or reference members  to support consistent terminology usage

• Query specification reference set

• Association reference set