The SNOMED CT Template Syntax is designed to convert any formal SNOMED CT language into a SNOMED CT Template Language. A SNOMED CT template contains slots, which provide a placeholder in the expression, constraint or query, whose specific value can be completed at a subsequent time using a value recorded within an information model, entered into a data entry form, or sourced by some other means.

Status

The SNOMED CT template syntax version 1.0 has been published at http://snomed.org/sts. This specification includes the SNOMED CT expression template language v1.0 - http://snomed.org/etl.

Implementations

SNOMED International is aware of the following implementations of the SNOMED CT Expression Template Language:

SNOMED International
- SNOMED Template Service: https://github.com/IHTSDO/snomed-template-service
- Generated parser and examples: https://github.com/IHTSDO/SNOMEDCT-Languages/tree/master/SnomedCTExpressionTemplateLanguage
B2i Healthcare - https://github.com/b2ihealthcare/snomed-etl
Nictiz Netherlands - https://github.com/mertenssander/postco

Future Versions

Additional requirements are being collected for consideration in future versions of the SNOMED CT Template Syntax. In the following sections, we describe some of these proposed requirements under consideration.

Support for an Expression Constraint Template Language

Adding guidance, syntax, and a model of input data to support the use of slots in the Expression Constraint Language.

Default Values

The ability to state the default value for a slot using the template syntax. For example .... [ slotName ws] [ "[ =" defaultValue "]" ]

Equal and Not Equal Values

The ability to say that the value of two slots must be equal, the value of two slots must be different, or the value of one slot must be subsumed by the value of another slot.

Conditional occurrence

The ability to say that an attribute is allowed to occur at most once in a role group. However, if the attribute is present, then it must be present in every repeat of that role group. - e.g. |Occurrence| attribute

See ticket #22789