ETSI EN 300 356-4-2001 综合业务数字网(ISDN).7号信令系统(SS7).国际接口的ISDN用户部分(ISUP)版本4.第4部分:主叫线路识别限制(CLIR)补充业务(版本4.2.1).ITU-T建议Q.731,
Integrated Services Digital Network (ISDN); Signalling System No.7 (SS7); ISDN User Part (ISUP) Version 4 for the International Interface; Part 4: Calling Line Identification Restriction (CLIR) Supplementary Service (V4.2.1; ITU-T Recommendation Q.731, Cl