{
    "properties": {
        "acquisition_source": {
            "description": "Source of acquisition (former 541)",
            "id": "#acquisition_source",
            "properties": {
                "date": {
                    "_format": "date",
                    "description": "Date of acquisition",
                    "type": "string"
                },
                "email": {
                    "_format": "email",
                    "description": "Email of submitter",
                    "type": "string"
                },
                "method": {
                    "description": "Method of acquisition",
                    "enum": [
                        "OAI",
                        "batchupload",
                        "submission"
                    ]
                },
                "source": {
                    "description": "Source of acquisition (e.g. ID of the user)",
                    "type": "string"
                },
                "submission_number": {
                    "description": "Internal submission number",
                    "type": "integer"
                }
            },
            "type": "object"
        }
    }
}