matrix-spec-proposals/event-schemas/schema/m.room.name

{
    "title": "RoomName",
    "description": "A room has an opaque room ID which is not human-friendly to read. A room alias is human-friendly, but not all rooms have room aliases. The room name is a human-friendly string designed to be displayed to the end-user. The room name is not unique, as multiple rooms can have the same room name set. The room name can also be set when creating a room using ``/createRoom`` with the ``name`` key.",
    "type": "object",
    "allOf": [{
        "$ref": "core-event-schema/state_event.yaml"
    }],
    "properties": {
        "content": {
            "type": "object",
            "properties": {
                "name": {
                    "type": "string",
                    "description": "The name of the room. This MUST NOT exceed 255 bytes."
                }
            },
            "required": ["name"]
        },
        "state_key": {
            "type": "string",
            "description": "A zero-length string.",
            "pattern": "^$"
        },
        "type": {
            "type": "string",
            "enum": ["m.room.name"]
        }
    }
}