The SNOMED template syntax specification defines the formal rules for representing slots in SNOMED CT expressions, expression constraints or queries. A slot either provides information as to how the template should be processed, or represents a placeholder for a value that is not known at the time of authoring. These placeholders can be completed at a later time using data recorded elsewhere (such as in an information model or entered into a data entry form).

The template syntax may be used in conjunction with any of the computable SNOMED CT languages to represent templates of various kinds. For example, using the template syntax with compositional grammar enables the representation of expression templates, while using the template syntax with the expression constraint language enables the representation of expression constraint templates.

SNOMED templates can be used for a number of purposes, including to define reusable patterns for authoring and validating precoordinated concept definitions and postcoordinated expressions.