How should a paramete of type "data URL" be declared in an OpenApi schema

Is it possible to declare a parameter in an OpeanApi 3 schema as being "data URL"? If I understand the specification, the format can be basically anything, but should I use some specific format or should I just do it like this?

MyObject:
  title: MyObject
  description: Information about my object
  type: object
  required:
    - myData
  properties:
    myData:
      type: string
      format: data URL