2 Use Cases

When values within a SNOMED CT expression, expression constraint or query are unknown at the time of authoring, a SNOMED CT template may be used. The SNOMED CT template syntax can be used in conjunction with the SNOMED CT computable languages to create SNOMED CT template languages for this purpose. For example:

• Using the template syntax with SNOMED CT compositional grammar enables the representation of expression templates
• Using the template syntax with the SNOMED CT expression constraint language enables the representation of expression constraint templates

• Using the template syntax with the SNOMED CT query language¹  enables the representation of query templates.

This version of the SNOMED CT template syntax specifically focuses on supporting two important use cases in which the SNOMED CT template syntax is needed. In particular to support:

• Authoring of precoordinated concepts
• Defining consistent postcoordinated expressions

These use cases specifically require the use of slots within SNOMED CT Compositional Grammar. Therefore, this version of the specification focuses primarily on explaining the use of the template syntax within the context of the Expression Template Language. Other use cases for the Expression Template Language are briefly discussed in Other Use Cases for Expression Templates.

Future versions of this specification are expected to present additional template languages (e.g. the Expression Constraint Template Language), which share the common template syntax for representing slots.