The scope of this document is to develop an American National Standards (ANS) standard for testing services by extending the object model in ITU-T Recommendation X.745 for the purpose of testing Plain Old Telephone Service (POTS). This standard will allow service customers to request a test and to receive subsequent test results for one of their POTS services. Purpose The purpose of this document is to provide an XML schema interface (tML ServiceTest interface) for uncontrolled POTS Service Test function specified in clause 3.