Empfehlung der CCITT/ITU von 92-93: Stage 3 description for number identification supplementary services using signalling system No. 7 Clause 1 (02/92) Direct-dialling-in (DDI) Clause 3 (1993) Calling line identification presentation (CLIP) Clause 4 (1993) Calling line identification restriction (CLIR) Clause 5 (1993) Connected line identification presentation (COLP) Clause 6 (1993) Connected line identification restriction (COLR) Clause 8 (02/92) Sub-addressing (SUB).