Meeting Introduction

@Peter Williams

10

Share Screen.  Start recording.

Previous meeting

Housekeeping - Mics and Movement

Membership Changes, welcome to Keng-Ling Wallin & Jeff Pierson

Atlassian Migration. Forum membership.

Morphology Proposal

@Yongsheng Gao 

@stefan.schulz (Unlicensed)

30

https://docs.google.com/presentation/d/144SsNC5UDQ13YJQmqvIThbe7uT2leO8TM4GNm9Jfbaw/edit?usp=sharing

Ontological Remodelling of the Morphology Hierarchy - Google Docs.pdf

Handling meaning changes in terminology

@Yongsheng Gao

40

https://docs.google.com/presentation/d/1-RVwAbPo9S_EttybMXyA6tbn1pgUJcFPLf5DBnV1p10/edit?usp=sharing

Update to drug model for hydration

@Yongsheng Gao

30

https://docs.google.com/presentation/d/1FazubFbPm7OsGBFUDj3Qm_o8y46uluA-fY9IiPE1gc8/edit?usp=sharing

Relationship Characteristic Type Mutability

@Peter Williams 

10

https://docs.snomed.org/snomed-ct-specifications/snomed-ct-release-file-specification/component-release-file-specification/4.2-file-format-specifications/4.2.3-relationship-file-specification

Now this one I think should be immutable. Two pain points:

• Additional Relationships are not sent to the classifier (post-processing wrapper), and so if an inferred relationship is turned into an additional relationship, the classifier does not get informed about the loss, and continues to try to inactivate that relationship. We could potentially just swallow that change at the other end, but it still looks like a failure to fully classify to our validation checks.

• If a stated relationship (now historical) should switch to another type, then it would appear in two files. Systems which import into separate structures would not receive an inactivation in one ‘table’ to indicate that row is no longer active there.

Result: MAG agreed to mark this column as immutable. @Andrew Atkinson

LOINC Extension Update

@Peter Williams 

20

https://loincsnomed.org/

SNOMED CT Implementation Guide for the LOINC Ontology

New this release (2.0 aka 2025-09-21) - Groupers and Discouraged Annotation

Miscellaneous Modelling Issues

@Guillermo Reynoso

Looking at GCIs on Anemia being used as intermediate primitives

Necessary Intermediate Primitives

Planned Changes, not necessarily prioritized

@Peter Williams 

30

• FHIR Terminology Ecosystem - see 'todo' list item #7 from the SNOMED on FHIR agenda: 2025-04-06 - SNOMED on FHIR Meeting (TS & TB)

• Package Manager (Edition Manager) - specific issue with packaging 3rd party code systems (eg LOINC) with country extensions.  @Guillermo Reynoso "modules are too big" - would like to pick and choose concept inclusion (eg lateral promotion) @michael lawley a good 'picknmix' package manager would help encourage the use of smaller (ie more re-usable) modules.  @Dion McMurtrie brought in URI spec composition feature.  Simple case of derivative content (eg just simple refsets), translations, to most complex case with axiom content.  We're then talking about a new Edition.  Interoperable issue with SNOMED Codes appearing related to different URIs @Daniel Karlsson (Unlicensed) whether or not we use  the MDRS, there is still going to be a dependency between these modules.   @Guillermo Reynoso makes distinction between raw content bundling and actually referencing the content eg child concepts. @Brian Carlsen suggests "Edition Composer". 

• Removal of Template field from MRCM.  @Guillermo Reynoso would like to see this prioritized.   Also @Dion McMurtrie 

• Publishing of Templates.

• Use of Additional Relationships for metadata (already permissible in the specification (in use by AU?), limited business driver eg use case of BCP-47 language/dialect code for language refsets).  @Dion McMurtrie other metadata around meaning of fields in refsets.  Map source and target codesystems. Alternative solution in using annotations.  @Guillermo Reynoso is using additional relationships with Canada.

Welcome

@Peter Williams 

Meeting Parameters and Start Recording

Top Take-Aways from meetings this week

Have any decisions been made which are of general interest? Are there cross-cutting discussions you would like to continue here, that would benefit from a wider audience?

DEUSG - @Alejandro Lopez Osornio - NRC can submit a substance

CMAG - @Monica Harry - Content trackers for review by content managers for Q4.

EAG - @Jim Case - addition of attributes to physical model for specimen containers. Modelling of bypass and shunt procedures eg for removal. Relationships for Gene names

MAG - @Peter Williams @Yongsheng Gao

• Check with the TRAG - relationship characteristic type should be changed to an immutable field in the RF2 File Specification.

MSUG - @Terance Shird

Translation - @Ole Kristian Våge - specific discussion on eg hand

TRAG - @Andrew Atkinson - Spanish Edition moving to quarterly. Description length changing in INT July 2026. Package Metadata. Changes to release file spec

Package naming convention

@Andrew Atkinson

10

Proposal to be grouped together and presented to Member Forum

• Removal of Managed Service & RF2 tags.

• Add indicator for Edition / Extension contents (Jan 2026). Will also appear in Metadata files.

• Refset file name changes eg change from long names to refset ids.

• Remove the need for Delta files in packages from specification.

Deprecation of CNC Indicators

@Peter Williams

• Will be removed in 2025-01-01 International Edition

• International Authoring cycle for January commences ~13 November. Script will be run to inactivate all current CNC indicators (MAINT-2904)

• Same script will run for each MS customer as they upgrade to January release.

Previous notes: Deprecation of CNC indicators - @Andrew Atkinson discussion on full removal of CNC indicators (ie surgical removal from full and snapshot files for July 2026) and making available through a static resource package that can be loaded separately.  @Guillermo Reynoso requests further guidance for country extensions, particularly with a view to inactivating and removing content.

Community Consultations

@Peter Williams 

30

Description Length increase - @Linda Bird (Unlicensed) mentioned additional use case for chemo regimes that specify medicinal products used, but in procedure hierarchy. Will apply in International Edition from July 2026. Extensions can override this value sooner, if needed.

Super and Subscript (Documentation needed on use cases - coming mostly from Translation User Group). @Guillermo Reynoso would like to see technology independent markup. @Maël Le Gall noted issues with searching in the browser.  @Brian Carlsen Noted use of <sup> <sub> in UMLS.  @stefan.schulz (Unlicensed) noted that languages for which these characters are not considered 'special' do still expect searching to work for the 'base' character ie without the diacritic mark.   Also that keyboards often don't feature these characters.  @Daniel Karlsson (Unlicensed) Notes rules for folding are well published by UTF-8.  @Mikael Nyström (Unlicensed) Database config often allows for known character folding to be done per language.

22-10-2025 GR Removal of ASCII markup caused problems and also affects searching. Would like to see graceful evolution. Possible use of new description type eg to indicate html markup in use (once existed as ‘symbol’). SA Would like to see International guidance on this.

Drug Model Enhancements

@Guillermo Reynoso

Linda Bird

Hydrations - allowing subsumption of hydration modification substances at the clinical drug level.

Multi Component Clinical Drugs

Dose Form challenges

Deprecation policy

@Andrew Atkinson

1

Deprecation policy

Group was asked if communication with Member Forum and Release Channels (also via Forum) would be sufficient. General agreement that it was.

AOB / Items outstanding

@Peter Williams

5

Concept model for a condition without condition (@Jim Case and @Yongsheng Gao)

------------------------------------------

Role Grouping (in the context of BFO harmonization), see Reubmitted Manuscript

Post Coordination (impact of DL changes),   further ECL filtering.

Concept model for conditions caused by substances or products - to be circulated before January @Yongsheng Gao (incl. other AGs and Member Forum)

Yong's further items to discuss (quick chat if time allow, or create page to continue)

• Qualifying Attributes - we've called them that, but they're being used as defining attributes (this is more about documentation clarity)

Refset Descriptor Refset - Mandatory / Optional / Transitivity

@Peter Williams

5.2.4.1 Reference Set Descriptor

(Generate page for discussion)

Draft Design for Template Publication

@Peter Williams

Work in progress:  https://docs.google.com/spreadsheets/d/1hOKOu9kxTFvqlgY_Gzc3T-sn8Z-b-d1bH5-Ocn9Sz90/edit?usp=sharing

Production templates here:  https://github.com/IHTSDO/snomed-templates

GR Major Use cases: 

• MRCM refsets causing issues in computed templates.  Is considered redundant and is heavy overhead for extension.

• UUID for each logical template (Done!)

• Description templates also expected to be used and extended (for each language) by Termmed

• Critical to move forward with this work

DK Points out complexity of generating terms in non-English languages.  We agreed to look at additional use cases although existing design allows for use of RegEx and even small chunks of JScript so already quite flexible.

GR Description rules are most useful when used with sufficiently defined content.  Templated descriptions used with existing International Content could pick up elements from other languages eg use template to help parse the English term parts and translate those in context.  

GR Would like to see refset sample based on current production templates as per GitHub repo.   To be discussed internally @Rory Davidson @Andrew Atkinson

Future enhancements to the logic profile

Negation

Disjunction

Calculation not currently faster under M1 chip architecture.  Note that most of the time taken up by the classification service end-to-end process goes into generating the NNF, which is single threaded.

Refset Metadata

This topic comes from SNOMED on FHIR

Also TRAG item: Reference set metadata See Agenda item 17 and consider in wider context of machine readable metadata item 11

In fact, this metadata may be more widely useful when applied to a module.

Suggestion that we could use the FHIR standard which already defines metadata. DM suggests a JSON format which would be extensible unlike a column based solution.

Where are we at with this? Checking with @Andrew Atkinson

Revisit "Negative Delta"

@Peter Williams

At request of EAG - need to revoke/delete a published component. Comments added to Negative Delta.

See TRAG agenda item #

Notify @Andrew Atkinson

Use cases:

Two groups: where audit is desired (eg technical issue) and where it is not (IP, un-processable characters)

1. Removing IP - suggestion to blank out particular field ("~") while leaving row.

2. Conflicting Rows ie no clear state (technical issue, not content) - suggestion to subsequent delta clarifying row.

3. Clinically dangerous historical error in before-previous release.