supplementary service

基本解釋

Supplementary service: law firm, language training school, preparatory college, overseas school, employment agency.
配套服務：律師事務所、語言培訓學校、預科學校、海外學院、就業(yè)機構等。
The Sub-addressing (SUB) supplementary service allows the called (served) user to expand his addressing capacity beyond the one given by the ISDN number.
子尋址（SUB）補充業(yè)務允許被叫（被服務）用戶在給定的ISDN號碼基礎上擴展其尋址容量。
www.ptsn.net.cn
Because there's an essential signaling difference between IP phone and traditional voice service, IP phone supplementary service is developed based on special protocols.
由于IP電話系統(tǒng)在信令結構方面與傳統(tǒng)電話系統(tǒng)的集中模型有本質的區(qū)別，因此基于IP電話系統(tǒng)附加業(yè)務的開發(fā)和控制協(xié)議具有不同的特點。

The Unstructured Supplementary Service Data (USSD) code (which we won't reproduce here) apparently only works on Samsung phones running Touchwiz, and only if you are directed to the dodgy destination while inside the stock browser (rather than Chrome, for example).
ENGADGET: 'Dirty USSD' code could automatically wipe your Samsung TouchWiz device (updated)