What is "advocate-on-record"

Advocate on Record is an advocate who is entitled under the Order IV of the Supreme Court of India Rules, 1966 to act as well as to plead for a party in the Supreme Court of India. As per the Rules, no advocate other than an advocate on record shall be entitled to file an appearance or act for a party in the Supreme Court of India. No advocate other than an advocate on record can appear and plead in any matter unless he is instructed by an advocate on record.