"A best, good faith effort" would place on Participants the highest legal standard of care--possibly requiring an AD or WG chair to affirmatively search their IP portfolio and map the claims (~20 claims per patent) of each relevant patent against each IETF draft in their domain. Is it realistic to think that Cisco, Juniper, Huawei and others similarly situated would retain an army of IP professionals just to ensure that the AD/WG chair can meet this standard? Or will these companies just require that their employees no longer "Participate" in IETF activities? As far as non-IETF sanctions, you are probably thinking of the Rambus-JEDEC matter. I am not aware of any situation where an IETF Participant has consciously hidden patents while pushing an IETF standard, and then, once the standard has been adopted, asserted the patents. So long as a Participant is an active participant, that is, someone actively pushing the Contribution in some fashion, and not someone who "should have known", and is then consciously aware of possible IPR, only then does the duty to disclose arise. Best, Mike