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20:00 UTC on Tuesday 23 March 2021 - 90 minutes.   


  • FHIR Terminology Services and Resources

Discussion items



OwnerNotes & Actions
1Welcome and introductions2

Recording, notes & attendance.

2Summary of previous week and previous fortnight5
3Other Meetings5

Recent events:

Digital Health Rewired 15 - 19 March run by

See also

Upcoming events:

SI April Business Meeting - Virtual.  19 - 22 April.  Open door FHIR get-together for usual slot Tuesday 20 April.  Registration and Agenda now available.

FHIR Connectathon (GMT/ UTC) May 17, 2021 to May 19, 2021 - Virtual Event   IPS with UNICOM Proposal.  PJ See$expand?_format=json  Planning for Terminology Stream Proposal TBA - RH's main concern is ConceptMap. ML pre-implemented properties parameter in $expand.

FHIR Working Group May 24 - 28 will be UK time based. 

FHIR Dev Days June 7 - 10 (Virtual)  March 1 deadline for presentation proposals.  

SI October Expo - call for abstracts now open.


Discussion about URIs for ICD-11 MMS vs Foundation layer codes.  or /entity/<id>

5Topics for Terminology Binding Stream

Collecting topics for TB stream here, with a view to having a call when there's sufficient material

FamilyMemberHistory - how is "no family history of X" best represented?

FreshDesk ticket question on Allergy substance cross field validation.  DK: Mappings to other information models, is that helpful?

15 Dec 2020 DK Asking if the member forum are still keen to see engagement in this area - offer to help country implementations.   Difficult to make decisions on binding without a concrete use case.  ML We could look at / review IGs (DK As we did for COVID).

  • Suzy Royplease work with Daniel and Nick E. to take forward something appropriate for next MF (will be in the New Year).

12 Jan 2021 Update: Contact planned with the MF - next call (Jan 22) is topic based, so after that one - 2 Feb (with Daniel)

9 Feb 2021 Update: Briefing note (DK) ready to be presented to MF.   Now (23 Feb) submitted for discussion, waiting for date in March or April.

9 March 2021 Update: Daniel to present to MF on 11 March (Thursday!)

23 March Update:  Presentation given, awaiting feedback.   Reminder Suzy Roy?

6R4B Position2

Update on in-flight work in HL7 groups including "R4B" release.  See ongoing discussion.

Initial Balloting - January for Q2 publication.

R4B (R5 pushed further out) Initial ballot (for comment, scope confirmation) in May 2021.   Note Concept Map has dropped in maturity due to ongoing changes.  Further ballots September (Nov/Dec) with a view to publishing Q2 2022.

3 Nov 2020: Push to use terminology "properly" (eg correct URLs / URIs) linked to UTG tooling + process.  Still looking at changes for ConceptMap.

15 Dec 2020 Vocab Group Update R4B deadlines extended any items for ballot by the end of this week.   Plan to add additional concepts to ValueSet and keep working on extension (although not an official part of R4B).   What do we need to conclude to put the Designation Extension forward to be part of the core specification?

26 Jan 2021 Ballot sign-up starting Feb.  There must not be any breaking changes due to non-major-point release.

9 Feb 2021 :  R4B Branch now available for pull requests.  23 Feb: deadline for changes March 2.  Trimmed down release - brand new, critically important or backwards compatible tweaks.   No ConceptMap changes, see R5 for those balloting from May.

ML ConceptMap moving from R4 to R5.

9 March 2021: Last updates coming in, delayed due to tooling issues.   Balloting open in next few days.

7Modules as Code Fragments15Rob Hausam

Action item from the HL7 Vocab WG.  How FHIR code system (CodeSystem resources with content = fragment) could be used in representing SNOMED CT modules.

Need to include guidance specific to how fragment can be utilized to represent SNOMED modules. However, at this time. though technically SNOMED modules could be published as fragments, it is not done by either SNOMED Int or member countries production extensions.

We would also recommend that the SNOMED on FHIR group include some guidance on the use of fragments. If that is complete at the time of writing the VSD IG, we can point to that guidance also.   And this (in row 86) gives the fuller context.

9 Feb 2021  See discussion SNOMED CT and CodeSystem Fragments

23 Feb 2021: Use of CodeSystem Fragment in Sweden?  DK (from comment below): A Swedish SNOMED on FHIR user is using a fragment of SNOMED CT for some ValueSets and their system internally needs to refer to a certain version of the fragment. E.g. an additional code is needed in a value set and is added to the CodeSystem fragment creating a new version of the fragment. What would be a way to meet this requirement within the standard, if possible? ResponsesML thinks this is a gap in the standard - version field is that of the CodeSystem and doesn't allow for versioning of the fragment.   RH: The two should be aligned, the version of the CodeSystem is the version of the Fragment.  Also "Fragments can only be created by the CodeSystem publishers" (note: the Swedish NRC counts as a valid publisher of SNOMED).  ML: Could just release a new fragment without needing to version it?   xsct URI could be used with incremented date.    ML: problem with any two Fragments is that we dont' know if they overlap or relate to each other at all.  DK: GPS is the obvious valid use case for a fragment of SNOMED.  ML CodeSystem Supplement may have features to solve this problem as a re-articulation of the content.  

9 March 2021:   HL7 internal discussion about the use of Fragments (sometimes violating rule that Fragments should be approved by the CodeSystem publisher).   May have a need for "Subset" eg #1 for mapping to LOINC codes and only distributing the codes that are required (ValueSet expansion insufficient in this case)  #2 in Terminology Server where access to entire CodeSystem is not possible eg ATC (cherry picked from a browser).

Archive discussion.

8Publishing SNOMED codes in IGs and licencing conditions.

Licensing issues for IGs referring to SNOMED codes. Is this written down anywhere with some sort of rigour?

Consider the licence statement that is presented when accessing the browser. Should somethig similar be mandated for inclusion in any document published? What if a patient's medical record were to be published?

Update 12 Jan - "One Page Policy" to be discussed internally.   HL7 agreement indicates other parties would require affiliate licence unless they restricted their usage to the Global Patient Set.

26 Jan Question from PJ about inclusion of COVID Vaccine concepts in the GPS (advised that it is only released yearly)  FYI Rory Davidson See also MF discussion here.  SuzyR will follow up.  See also early preview page.

9Working 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.

11 Aug: Corrected the url listed above to the standard (not 'xsct'). Michael would still like to progress this. Needs further discussion in SNOMED Family of Languages group. Need for this is surfacing in Queensland Health.

10 Oct: follow up if Languages group went down the road of modifying the URI.   Also questions of composition where sibling packages are involved (eg both dependent, but separately, on the international edition).  Update - yes is on agenda.

12 Jan: This has (today) been implemented in snowstorm - xsct is preferred (PW says) because it has precedent in a way that "UNVERSIONED" does not, and (ML says) is more flexible because it can be used along with a version string. 

26 Jan URI formed with xsct now available in Snowstorm master branch see documentation examples.  Also implemented by Ontoserver.   Should we update the HL7 SNOMED page?   TODO Propose update to "Version" section of   eg strengthen "should" to "shall".

  • Peter G. Williams raise tracker to suggest inclusion of "unpublished" URI.    Discuss with Linda Bird Update 23 Feb - Email sent to Linda.
  • Peter G. Williams  create page to bottom out issues.  Update :  Lots of other things to think about eg Alpha/Beta packages (where effective time is specified and in the future).  Create page to go through further discussion.
10Language 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

Update 17 Nov:  Proposal to add more values into designation use

Update 1 Dec: Latest build:   Ticket: being replaced by   ML suggested we need an additional value for 'Not Acceptable' that would need an additional value to be explicit, rather than relying on the absence of a 'row'.   Designation Use codeset, or the infrastructure codesystem?  See also

Update 15 Dec:  Discussing cardinality - when a designation can be applied to multiple roles, do we have repeated elements in a single extension block, or multiple extension blocks?  PJ Checking use case.    Use Case:  To allow tell the client what all use contexts (roles) are available so that it can a) select one making an informed choice and b) gradual degradation where the best available terms are used where they exist, falling back to a less preferable term where they do not.  Worked example from ML    also 
On question if this should be part of core spec or remain in SNOMED IG we can consider if this is of use to any other Terminology eg LOINC or RxNorm.

12 Jan Update: Rob Hausam looking for clarity to take forward with Vocab group.   How to align this with other in-flight trackers (eg that propose expanding designation use which - we think - seeks to overload designation use in a way that wouldn't ( ?) allow more than one value at the same time and these features of designations can vary independently.

12 Jan Proposal:   All 3 elements (including designation type) should be included in our proposed extension.   SNOMED implementations would then pick the most appropriate designation.use value from whatever set is offered in the spec   eg FSN where it is an FSN (because - although also considered 'preferred' - these are seldom used for user interfaces), PreferredForLanguage where we have the preferred term for a given language/dialect and Synonym for anything else.

26 Jan: RH update - is ongoing discussion.  Attempting "best of both worlds" approach.  Not on the Vocab group's agenda, won't be in R4B.    Question from ML about display vs preferredForLanguage here.  Proposed extension to list of designation use will necessitate repetition of designations where they have multiple uses.   See DK example here:

RH: Suggestion that Ontoserver and/or Snowstorm could try an implementation of our extension.   Clients are expected to ignore extensions that they don't understand.

9 Feb 2021 ML Experience with NL and LOINC.  Could we explore using Language tag with a private X language (eg nl-x-sctlang-87587989-78574801 BCP 47: privateuse = "x" 1*("-" (1*8alphanum)) ) and the language reference set id - ie allows for things like Patient Friendly Terms.   The preferred term would be mapped to the display element.   Language tags allows for weighted preferences (ie fall back options).  Pros:  avoids an extension and re-uses an existing part of the specification.  DK "No reason not to implement this, the two approaches are not in conflict".   Question: is "Preferred for Language" definitely happening?   RH: Yes

23 Feb 2021 RH brought up discussion with Vocab group.  Check in on tracker UP-107. DK Still a requirement to present results (eg expansion) with the language refsets visible (to know which designation was in which langrefset) - better to use extension or overload core spec?   Querying is fine, issue is making clear what is being returned. Suggested possible to use the BCP47 refset form in the language element.   Difficulty when returning fall back options as display term is that we can't say what we fell back to.

9 March 2021 DK An implementation is now needed.   DK tried out with Snowstorm:  BCP-47 works but not for extension language referencesets (also for designation)  ( note dialect alias configured in is a separate solution which could also be improved: ).  SM NL BCP-47solution getting great feedback.

23 March 2021 DK Testing Snowstorm which looks at designation and language headers.   Just needs attention especially for extension content.  

11SNOMED 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:    Structure for FHIR event at SI Business Meeting - lessons learned, review of terminology servers (comparison page).

Potential Items for Discussion

OwnerNotes & Actions
SNOMED Family of Languages

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)

8 Sept The FHIR specification does not specify a particular version of ECL, so we assume the latest.  Any enhancements added to ECL will be immediately relevant and available in FHIR.   Note that these latest additions while targeting descriptions are a concept filter, so display options (language etc) will affect the output of those concepts.   How about the filter parameter though, especially since ECL would allow multiple filters in multiple/different languages.

  • Michael Lawley Suggested ticket: Parent and Child properties to (optionally?) support the Coding type.
Specify CodeSystem in FSH
FSH apparently has no way of specifying the version of a CodeSystem. Daniel checking the ANTLR spec.
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


$lookup operation - properties returned

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?

Concluded Discussion

See also FHIR Terminology Services Discussions

OwnerNotes & Actions
Terminology Capabilities

Terminology Capabilities: Default SNOMED Edition for a Server. Suggestion to invite Graham for a wider discussion. Resource is still at maturity 0.

11 August The resource is based on instances of code systems. Difficult to make statements about code systems generally, or specific SNOMED editions, etc. Will start a Zulip discussion on this. Michael Lawley Then potentially invite Grahame for a future discussion?

25 August It has been agreed that this resource will now have maturity level 1

New parameters proposed for streamlining operation of expand and validate code
Grahame Grieve


8 Sept 20 Is there a Jira ticket ?   Rob says Grahame implemented this.

12 Jan:  RH update made to GG Server.   Documentation (assuming required) still outstanding.

FHIR 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.

Aug 25: New capabilities in HAPI to allow delegation to an external terminology server.

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