Public confidence in law and lawyers may be eroded by irresponsible or improper conduct of a lawyer. On occasion, ethical conduct of a lawyer may appear to laymen to be unethical. In order to avoid misunderstandings and hence to maintain confidence, a lawyer should fully and promptly inform his client of material developments in the matters being handled for the client. While a lawyer should guard against otherwise proper conduct that has a tendency to diminish public confidence in the legal system or in the legal profession, his duty to clients or to the public should never be subordinate merely because the full discharge of his obligation may be misunderstood or may tend to subject him or the legal profession to criticism. When explicit ethical guidance does not exist, a lawyer should determine his conduct by acting in a manner that promotes public confidence in the integrity and efficiency of the legal system and the legal profession.