Service of an order to show cause instituting a formal disciplinary proceeding shall be made by personal
service or by registered or certified mail addressed to the respondent-attorney at the address shown in
the most recent registration statement filed pursuant to General Rule 17.1 hereof. Service of any other
papers or notices required by these Rules shall be deemed to have been made if such paper or notice is
addressed to the respondent-attorney at the address shown on the most recent registration statement
filed pursuant to General Rule 17.1 hereof; or to counsel or the respondent's attorney at the address
indicated in the most recent pleading or other document filed by them in the course of any proceeding.
