Update guidance on naming of classification schemes

[jpmckinney]

https://standard.open-contracting.org/staging/1.2-dev/en/guidance/map/organization_classifications/

The general guidance ought to be along the lines of:

• all uppercase, if the scheme is an acronym, e.g. CPV
• camelCase, if the scheme is universal
• {ISO-3166-1 alpha 2}-{suffix}, if scheme is scoped nationally, e.g. US-ABCD
• {ISO-3166-2}-{suffix}, if scheme is scoped subnationally, e.g. US-OR-ABCD

This is consistent with https://extensions.open-contracting.org/en/extensions/coveredBy/master/#guidance

We should link to the new guidance from https://extensions.open-contracting.org/en/extensions/organizationClassification/master/

In the examples, we should change "COL" to "CO". We can add an admonition about TED_CE_ACTIVITY and TED_CA_TYPE, to explain that they don't conform to our guidance, because we aimed for consistency with the XML elements in the TED Schema. (At the same time, we can update to the 'eu-main-activity' and 'eu-buyer-legal-type' schemes).

Related, we should change this page to use alpha-2: https://standard.open-contracting.org/staging/1.2-dev/en/guidance/map/organization_personal_identifiers/

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For reference, https://github.com/open-contracting/standard-maintenance-scripts/blob/main/schema/codelist-schema.json sets the allowed patterns for codes, some of which are relevant for scheme codes:

• acronyms: [A-Z]+[0-9]? (the only numeric acronym is ISO2 for the ISO 3166-1 alpha-2 gazetteer)
• camelCase, including at most one subcode, and allowing a 'oc4ids' prefix and EU and GPP acronyms: ([a-z]+|oc4ids)([A-Z][a-z]+|EU|GPP)*(\\.[a-z]+([A-Z][a-z]+)*)?
• ISO 3166 scoped schemes, with hyphens and uppercase: [A-Z]{2}(-[A-Z]+)+

Exceptional patterns, to match multinational standards:

• TED XML Schema elements (to match TED style): TED(_[A-Z]+)+
• EU authority table names (to match eForms style): eu(-[a-z]+)+

These patterns are not relevant for scheme codes (they are examples of being consistent with other standards):

• JSON Schema types: date-time
• GeoJSON geometry types: LineString|Point|Polygon|MultiLineString|MultiPoint|MultiPolygon
• IANA Media Types: (application|audio|font|example|image|message|model|multipart|text|video)/[\w.+-]+

[odscjen]

We can add an admonition about TED_CE_ACTIVITY and TED_CA_TYPE, to explain that they don't conform to our guidance, because we aimed for consistency with the XML elements in the TED Schema. (At the same time, we can update to the 'eu-main-activity' and open-contracting/european-union-support#208 schemes).

Do you mean that the example (2.1) on https://standard.open-contracting.org/staging/1.2-dev/en/guidance/map/organization_classifications/ should be updated to the use the eForms codes/schemes rather than the TED ones? So the admonition should mention both TED and eForms schemes?

[odscjen]

In the examples, we should change "COL" to "CO".

Noting that the examples that will be affected by this are included in #1680 so it's probably best to wait until that PR has been merged before creating a PR for this issue to avoid merge conflicts

[jpmckinney]

Do you mean that the example (2.1) on https://standard.open-contracting.org/staging/1.2-dev/en/guidance/map/organization_classifications/ should be updated to the use the eForms codes/schemes rather than the TED ones? So the admonition should mention both TED and eForms schemes?

We should update it to eForms, in which case we only have an admonition for the eForms schemes (since the TED schemes will no longer be part of the examples).