Rule 42C - Temporary Practice by Foreign Lawyers(a) A lawyer who is admitted only in a non-United States jurisdiction shall not, except as authorized by this Rule or other law, establish an office or other systematic and continuous presence in this jurisdiction for the practice of law, or hold out to the public or otherwise represent that the lawyer is admitted to practice law in this jurisdiction. Such a lawyer does not engage in the unauthorized practice of law in this jurisdiction when on a temporary basis the lawyer performs services in this jurisdiction that: (1) are undertaken in association with a lawyer who is admitted to practice in this jurisdiction and who actively participates in the matter;(2) are in or reasonably related to a pending or potential proceeding before a tribunal held or to be held in a jurisdiction outside the United States if the lawyer, or a person the lawyer is assisting, is authorized by law or by order of the tribunal to appear in such proceeding or reasonably expects to be so authorized;(3) are in or reasonably related to a pending or potential arbitration, mediation or other alternative dispute resolution proceeding held or to be held in this or another jurisdiction, if the services arise out of or are reasonably related to the lawyer's practice in a jurisdiction in which the lawyer is admitted to practice;(4) are not within paragraphs (2) or (3) and(i) are performed for a client who resides or has an office in a jurisdiction in which the lawyer is authorized to practice to the extent of that authorization; or(ii) arise out of or are reasonably related to a matter that has a substantial connection to a jurisdiction in which the lawyer is authorized to practice to the extent of that authorization; or(5) are governed primarily by international law or the law of a non-United States jurisdiction.(b) For purposes of this grant of authority, the lawyer must be a member in good standing of a recognized legal profession in a foreign jurisdiction, the members of which are admitted to practice as lawyers or counselors at law or the equivalent and subject to effective regulation and discipline by a duly constituted professional body or a public authority.