{
  "$schema": "http://json-schema.org/draft-03/schema#",
  "id": "http://popoloproject.com/schemas/membership.json#",
  "title": "Membership",
  "description": "A relationship between a person and an organization",
  "type": "object",
  "properties": {
    "id": {
      "description": "The membership's unique identifier",
      "type": ["string", "null"]
    },
    "label": {
      "description": "A label describing the membership",
      "type": ["string", "null"]
    },
    "role": {
      "description": "The role that the person fulfills in the organization",
      "type": ["string", "null"]
    },
    "person_id": {
      "description": "The ID of the person who is a party to the relationship",
      "type": ["string", "null"]
    },
    "person": {
      "description": "The person who is a party to the relationship",
      "$ref": "http://popoloproject.com/schemas/person.json#"
    },
    "organization_id": {
      "description": "The ID of the organization that is a party to the relationship",
      "type": ["string", "null"]
    },
    "organization": {
      "description": "The organization that is a party to the relationship",
      "$ref": "http://popoloproject.com/schemas/organization.json#"
    },
    "post_id": {
      "description": "The ID of the post held by the person in the organization through this membership",
      "type": ["string", "null"]
    },
    "post": {
      "description": "The post held by the person in the organization through this membership",
      "$ref": "http://popoloproject.com/schemas/post.json#"
    },
    "start_date": {
      "description": "The date on which the relationship began",
      "type": ["string", "null"],
      "pattern": "^[0-9]{4}(-[0-9]{2}){0,2}$"
    },
    "end_date": {
      "description": "The date on which the relationship ended",
      "type": ["string", "null"],
      "pattern": "^[0-9]{4}(-[0-9]{2}){0,2}$"
    },
    "contact_details": {
      "description": "Means of contacting the person who is a party to the relationship",
      "type": "array",
      "items": {
        "$ref": "http://popoloproject.com/schemas/contact_detail.json#"
      }
    },
    "links": {
      "description": "URLs to documents about the membership",
      "type": "array",
      "items": {
        "$ref": "http://popoloproject.com/schemas/link.json#"
      }
    },
    "created_at": {
      "description": "The time at which the resource was created",
      "type": ["string", "null"],
      "format": "date-time"
    },
    "updated_at": {
      "description": "The time at which the resource was last modified",
      "type": ["string", "null"],
      "format": "date-time"
    },
    "sources": {
      "description": "URLs to documents from which the membership is derived",
      "type": "array",
      "items": {
        "$ref": "http://popoloproject.com/schemas/link.json#"
      }
    }
  }
}