Mark’s practice focuses on trademarks, copyright, and litigation with an emphasis on trademark protection and enforcement issues including trademark infringement, passing off, and opposition and cancellation proceedings. Mark regularly appears before the Trademarks Opposition Board and in federal and Ontario court proceedings concerning trademark and copyright matters. He has also been co-counsel in a number of leading trademark cases concerning the rights of foreign trademark owners in Canada, trademark infringement on internet websites, and challenges to the rights of public authorities and universities to control the use of certain words and marks in Canada. Mark was chairman of the international trademark laws committee of the American Bar Association section of intellectual property law for the 2022–23 term. Mark has been actively involved with the Intellectual Property Institute of Canada (IPIC) having assisted in organizing, moderating, and presenting numerous IPIC educational seminars and meetings.