App was rejected for use of protected 3rd party material

My app has been rejected due to 3rd party material clause: > 8.5: Use of protected 3rd party material (trademarks, copyrights, trade secrets, otherwise proprietary content) requires a documented rights check which must be provided upon request. 1, What is **documented rights check** composed of 2, How do I offer it up to Apple so that my App is approved.