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20:00 UTC on Tuesday 30 June 2020 - 90 minutes.   


  • FHIR Terminology Services and Resources

Meeting Details


Phone: See for available phone numbers (meeting id 242-348-6949) # snomed-hl7-fhir (ask for invite!)

Zulip Chat:


 Rob HausamPeter G. WilliamsPeter JordanMichael Lawley


Meeting Recording

Discussion items



OwnerNotes & Actions
1Welcome and introductions2

Recording, notes & attendance.

2Summary of previous week and previous fortnight5
3Other Meetings10

Upcoming events:

30 June Suggestion to have a joint session 7 July to look at the IG and FSH (postponed from this week due to Daniel Karlsson vacation)

FHIR Dev Days also an online event June 15 - 17. Introduction to SNOMED with FHIR video here (free registration required)

HL7 Baltimore Sept 19 - 25. Confirmed fully virtual event. Connectathon Sept 9 - 11 (two weeks earlier)

SI Business + Expo October Lisbon. Confirmed fully virtual event. SNOMED on FHIR Presentation.

November FHIRLY Dev Days expected.

4R4A Position15Rob Hausam

R4A probably not going to happen in the previously proposed form. More likely now to be an interim release of R5.

Continued discussion around the direction semantics for maps. Current state:

5$translate with version30

In the case of SNOMED, the system will as always be just

PWI advised that the crucial factor is the location of the map. The edition of the source and target is not important, so the use of the version parameter is prohibited. eg url=

ML says Ontoserver uses conceptMapVersion for this as well because concept maps that do not use a url in this way also need to be able to specify a version. Suggestion that the version parameter might be used if the conceptMapVersion is not specified.

6Use of effective time parameter in $lookup15Michael Lawley

Suggestion that effectiveTime be added as a SNOMED specific property in the specification, raised by Peter Jordan in

The effective time of the concept (as represented in the concept file) does not necessarily capture when it came into its current state since relationships (inferred or stated) could change independently. Arguably we should use the most recent change to any of concept, relationships, descriptions. And what would we expect to happen in the case of filtering. ML: Ontoserver uses the date in the concept file because it's not possible to know what the enquirer's use case is.

7Use of system and version parameters in Lookup and Subsumes15

Clarification that system parameter is the "class" of the code system and so is always in our case. The instance of the code system ie a specific extension and effectiveTime should be supplied in the version parameter. Snowstorm and Ontoserver are aligned in this regard.. In the case of SNOMED CT we use a URI to declare our instance and so the system is entirely redundant in our specific case and the decision was made to not insist in it's use for Snowstorm.$lookup?version=

DK: FSH apparently has no way of specifying the version of a CodeSystem. Daniel checking the ANTLR spec.


GPS and FHIR value set url(s)


  • Peter G. Williams follow up on GPS as a published reference set to allow for simple definition as a ValueSet using the memberOf operator.
9What module(s) to use for the Canadian Edition10Peter G. Williams
10Working with unversioned content15

Proposed example: http://localhost:8080/fhir/ValueSet/$expand?url=

ML makes the case that unpublished content is not legitimate SNOMED and suggested using a not-SNOMED URI eg in this case the code system would still be

Outstanding question: our pre-release (alpha + beta) packages do have a version as a future date in them, and continue to exist (although unpublished) even after the official release has shipped.

How would this look in a ValueSet expansion? Should we specify systemVersion or forceVersion in this case?

Update 2 June: LOINC have a similar issue with "Pre-release" identifiers - current release 2.6.7. Version 2.6.8PRE will contain the pre-release content. "To be useful they need to be considered part of the code system"

However in the case of SNOMED CT we would NOT condone unpublished identifiers being used in production systems. In the case of the COVID-19 concepts an interim release was done as an official release for 20200309. The use case here is for producers of SNOMED CT to reference concepts internally - as a work in progress.

11FHIR Roadmap5Peter JordanR5 being pushed back. GG seeking opinion on 4.1.0 - an opportunity to clean up some descriptions.
12FHIR Server Federation10

Use case for fall back lookup when server does not know the answer to any particular question eg a façade server which has knowledge of all services it could potentially delegate to.

13Language Reference Sets in FHIR45All

Mechanisms for working with Languages

Designation extension

Update 19 May: Suggestion that we work an example for SNOMED to discuss with Regenstrief (LOINC)

Update 2 June: Started worked example Designation Extension Example

14SNOMED Family of Languages10

Impact of proposed changes (eg text searching in ECL) on FHIR. Questions around which language reference sets to use when there are multiple, especially partial/overriding context (referred to MAG for discussion)

15SNOMED FHIR Implementation Guide60

Implementation Guide for using SNOMED CT with FHIR.

Update 10 Dec: DK - main problem is URI/Ls which publisher has fixed ideas about. Publisher does not examine all folders - looks in profiles but not subfolders and doesn't seem to look in ValueSet folder.

Update 21 Jan: DK and RH have merged commits and these can be seen in the HL7 server build: and build errors here:

Update 11 Feb: Grahame said that he'd show us how to set the URI so that it doesn't have to follow the base URI. Next person to try that can we fire a Zulip off to ask about it?

Update 16 June: DK wondered about moving everything to FSH (FHIR Short Hand) as it's so much easier to maintain. ML: Conversion available, but round trip problematic. DK page Re: snowstorm FHIR requirements, issues, etc.

IG Documentation:

Also look at the sample IG see build


Any other business

Next time: ML Post coordination - primitive <<< syntax, what does this mean in practice?

Potential Items for Discussion

OwnerNotes & Actions
API for FHIR Resource ↔ Post coordinated expression mapping

API for FHIR Resource to SNOMED Expression

  • Daniel Karlsson Thought there might be some documentation from CIMI on this. Also notes from DMarkwell about constructor bindings.
  • Peter G. Williams Pull these notes into confluence - can we mention it in the IG?
Looking up an SCTID in an unknown module

Problems when dependencies do not align. Multiple code system resources represent multiple editions / versions.

ML: See code parameter to code system search. Should return code systems (ie versions) where that code is defined. International concepts would appear in every edition known to the server.

eg /CodeSystem?system=htp://


See Discussion on Global Patient Set (GPS)
FHIR Shorthand
Michael Lawley


$lookup operation - properties returned
Peter Jordan

Using  I noticed that both Ontoserver and SnowStorm return a SNOMED CT $lookup property for effectiveTime, which I don't see listed, as one of the SNOMED CT properties in the FHIR R4 specification at Should we create a Jira TIcket to add this?

Completed -

Use of url parameter15

CodeSystem "class vs instance" in url parameter between CodeSystem and ValueSet operations.

CodeSystem is understood.

In Valueset, url is the ValueSet url for example url = allows for the version URI to be used as stated in The base URL is either , or the URI for the edition version, in the format specified by SNOMED International in the SNOMED CT URI Specification.

The ValueSet version valueSetVersion is just some string identifier eg a timestamp or 0.1.0

ECL in the Valueset Expression Extension10

Check whether SNOMED ECL is (or should be) registered as a MIME type (as per RFC 4289/BCP 13), or alternatively added to the expression-language code system and value set, for use in the valueset-expression extension used with the ValueSet resource.

For example, HL7 have registered application/json+fhir

This is useful for a ValueSet extension which allows any language to be used to define the selection criteria for an intensional definition using a MIME type. This group has no current reason to use that extension given the existing core specification support for implicit ValueSet definition and the support within the compose element.

RDF community may have an interest.

Update 2 June RH: Existing small valueset extended in BCP13 (existing known codes could be published as a CodeFragment). Vocab Working Group discussion ongoing.

Behaviour on Lookup10

What properties are returned?

Discussion: Both Ontoserver and Snowstorm are returning EffectiveTime which is not listed here (unlike other SNOMED specifics):

Point of interest: Grahame's server returns a copyright property.

Update 7 April - Question about whether this is required / desirable?

Meeting Files

  File Modified
ZIP Archive 2020-Jun-30 by Peter G. Williams
PNG File image2020-6-30_21-16-3.png 2020-Jun-30 by Peter G. Williams