CONTENTS

 Introduction       iv
 1     Methods of validation
 2     Full validation procedures
        2.1     Validation information flow
        2.2     Authorization request
        2.3     Request response
        2.4     Call disposition (optional)
 3     Limited validation procedures
        3.1     Types of limited validation procedures
        3.2     Location of personal identifying information
Annex  A  –  Security during validation over an X.25 network
        A.2     Recommendations
        A.3     Validation security procedures