FINRA Rule 2010 (a member firm shall observe "high standards of commercial honor and just and equitable principles of trade") is FINRA's catch-all as to behavior that the regulators do not like, but as to which there is no specific prohibition. Because the Rule is so open-ended, violations of the Rule likewise can relate to a very broad range of topics from underwriting conduct to interactions with retail customers. In fact, FINRA so routinely tacks on a Rule 2010 violation to almost any other violation of the FINRA Rules to the extent that the Rule has almost ceased to have any meaning beyond the fact one has been found in violation of some other FINRA Rule. MSRB Rule G-17 (the obligation of an MSRB member to "deal fairly with all persons" and not to engage in any "unfair practice") is the MSRB's catch-all equivalent. See also the topic page on Muni Fair Dealing.