ITU-T D.151-1989 Old System for Accounting in International Telephony - General Tariff Principles - Charging and Accounting in International Telecommunications Services (Study Group III) 2 pp
The new system for accounting (Recommendation D.150) might not always be applied in some relations
especially where radiotelephone circuits are used and, in these cases, the following provisions may be adapted appropriately
ITU-T D.151-1989 history
1989ITU-T D.151-1989 Old System for Accounting in International Telephony - General Tariff Principles - Charging and Accounting in International Telecommunications Services (Study Group III) 2 pp