{
    "$schema": "http://json-schema.org/draft-04/schema#",
    "id": "crs.json#",    
    "title": "crs",
    "description": "a Coordinate Reference System object",
    "type": [ "object", "null" ],
    "required": [ "type", "properties" ],
    "properties": {
        "type": { "type": "string" },
        "properties": { "type": "object" }
    },
    "additionalProperties": false,
    "oneOf": [
        { "$ref": "#/definitions/namedCrs" },
        { "$ref": "#/definitions/linkedCrs" }
    ],
    "definitions": {
        "namedCrs": {
            "properties": {
                "type": { "enum": [ "name" ] },
                "properties": {
                    "required": [ "name" ],
                    "additionalProperties": false,
                    "properties": {
                        "name": {
                            "type": "string",
                            "FIXME": "semantic validation necessary"
                        }
                    }
                }
            }
        },
        "linkedObject": {
            "type": "object",
            "required": [ "href" ],
            "properties": {
                "href": {
                  "$ref": "../../schema.json#definitions/url"
                },
                "type": {
                    "type": "string",
                    "description": "Suggested values: proj4, ogjwkt, esriwkt"
                }
            }
        },
        "linkedCrs": {
            "properties": {
                "type": { "enum": [ "link" ] },
                "properties": { "$ref": "#/definitions/linkedObject" }
            }
        }
    }
}