Codelists

[BobHarper1]

I've added a number of codelists for properties in the schema as a starting point.

I'm proposing making these closed and open codelists (like with OCDS).

Open codelists:

• Activity
• Purpose

Closed codelists:

• Asset lock
• Deal status
• Organization type
• Loan type

Closed codelists are typically discrete and limited options, while open codelists are classification systems that don't have the same degree of consensus or comparability across publishers. Open codelists can therefore be extended to allow non-present values to be used if no appropriate value exists in the codelist.

You can get a good sense of this in the version of the documentation for this branch (codelists).

Example of an open codelist in the schema (part of the Organization object):

"activities": {
      "description": "An activity is carried out by an enterprise to support their mission, drawn from the [activity codelist](http://spec.socialeconomydatalab.org/en/latest/schema_reference/codelists/#activity).",
      "type": [
        "array",
        "null"
      ],
      "items": {
        "type": "string"
      },
      "codelist": "activity.csv",
      "openCodelist": true
    }

Example of an closed codelist in the schema (part of the top-level Deal object), which uses the code options in the enum field:

"status": {
      "title": "Status",
      "description": "Current status of the social investment deal based on the [dealStatus codelist](http://spec.socialeconomydatalab.org/en/latest/schema_reference/codelists/#deal-status).",
      "enum": [
        "open",
        "withdrawn",
        "completed",
        "pipeline",
        null
      ],
      "codelist": "dealStatus.csv",
      "openCodelist": false
    }