Rec. ITU-T D.232 (rev.1) (06/1992) … SPECIFIC TARIFF AND ACCOUNTING PRINCIPLES APPLICABLE TO ISDN SUPPLEMENTARY SERVICES
FOREWORD
1 Introduction
2 Charging aspects
    2.1 Number identification
    2.2 Direct Dialling-In and Multiple Subscriber Number
    2.3 Call Forward and Call Transfer
    2.4 Line Hunting
    2.5 Call Waiting and Call Hold
    2.6 Conference calls
    2.7 Closed User Group
    2.8 Advice of Charge
    2.9 Priority service
    2.10 Multi-level Precedence and Preemption Service
3 Accounting
4 Charging mechanisms and support requirements
ANNEX A … Summary of charging mechanisms and support requirements for supplementary services
ANNEX B … Alphabetical list of abbreviations used in this Recommendation