> For the complete documentation index, see [llms.txt](https://docs.snomed.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snomed.org/snomed-ct-specifications/snomed-ct-editorial-guide/readme/editorial-guide-change-log.md).

# Editorial Guide Change Log

### For **key** Editorial Guide changes, see the [Summary of changes](https://docs.google.com/spreadsheets/d/1xHZNeNQwkCcUPaZGEl28GFGv_WMTHZoeHeAV5cSjOFU/).

For past document releases, see the [Editorial Guide releases](https://github.com/SNOMED-Documents/snomed-editorial-guide/releases).

#### Release History Overview

<table><thead><tr><th width="163.79974365234375">Release date</th><th>Summary</th></tr></thead><tbody><tr><td>September 2026</td><td><p>Organism guidance was substantially revised: the "Addition of new organism concepts" section was replaced with a more detailed "Organism inclusion criteria" section (microorganisms, macroorganisms, Veterinary Extension, breeds, taxonomic rank), the naming conventions page's PT selection guidance was reorganized into numbered rules, and Salmonella serotype nomenclature was renamed/restructured as Salmonella serovar nomenclature.</p><p>Case significance guidance was reorganized into new "Organism naming" (with a Vaccinia example) and "Genes and genetic diseases" subsections, and the FSN page now lists gene names as an exception. A new Stoma procedures page was added covering stoma-vs-anastomosis distinctions, naming, and role-group modeling.</p></td></tr><tr><td>August 2026</td><td><p>This release covers about ten months of Editorial Guide updates since September 26, 2025.</p><p></p><p>It substantially expands and restructures Authoring guidance for domain-specific modeling. Coverage includes Body Structure, Clinical Finding and Disorder, Physical Object, Procedure, and Substance.</p><p></p><p>New and revised pages add naming conventions, defining-attribute guidance, and MRCM-based attribute tables. The release also adds focused guidance for substance groupers, substance types, and procedure attributes. Navigation and links have been reorganized. New diagrams and screenshots support the guidance.</p></td></tr><tr><td>September 2025</td><td><p>This was the first release after migrating from Confluence to GitBook.</p><p>It reflects the September 2025 version. Content did not change. The structure was adjusted for the GitBook layout.</p></td></tr></tbody></table>


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