Additions to the SNOMED URI Standard

The proposal is to support the following:

• http://snomed.info/syntax/scg   as the name of the SNOMED CT Compositional grammar (with additional syntax codes: ecl, qry, sts, etl, ctl, qtl)

• http://snomed.info/syntax/scg/version/1.1  as the name of a particular version of scg and

• http://snomed.info/id/74400008 as the concept identifier "74400008" and

• http://snomed.info/scg/74400008 as the URI encoded compositional grammar expression with one focus code.

For more details, please refer to the discussion at https://snomed.atlassian.net/wiki/display/SLPG/URI%27s+for+SNOMED+CT+Languages.

Questions and Answers

QUESTION 1 - How do you represent expressions that do not have SCT identifiers?

Here are some possible examples:
http://snomed.info/scg/404684003:47429007=267038008
http://snomed.info/ecl/%3C404684003:%3C%3C47429007=%3C%3C267038008 (where %3C is "<")

QUESTION 2 - Is the versioning system for SCG documented? What triggers transitions from minor to major versions ?

The revised version of Compositional Grammar defines itself as version 2.0, and 2 minor corrections in the text moved it on to 2.02
The Expression Constraint Language is documented as v1.0, and we were planning to publish some functional additions to this as v1.1.
As far as I know, we don't have any formal rules as to what triggers transitions between minor and major versions - however this is an area that would probably benefit from more rigour.
I would suggest that we should probably be following the semver industry standard (semver.org) - although we haven't been doing so to date. To summarize semver:

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