spec-enum.yml

swagger: '2.0'
info:
  version: '1.0'
  title: Example API
schemes:
  - http
paths:
  /myendpoint1:
    get:
      summary: Endpoint
      responses:
        200:
          description: Response
          schema:
            $ref: '#/definitions/Response1'


definitions:
  Response:
    type: object
    properties:
      prop_name:
        description: Response code
        type: string
        enum: [ Capital, UPPER, lower, snake_case, 'illegal+id' ]