Deck Codes History

Does anyone know when flashing of ledger boards started being part of the international standards?

Checking for it has always been a part of www.nachi.org/comsop.htm

http://education.nachi.org/show.php?course_id=64&element_id=1559

Thanks, Nick. Is flashing required over all ledgers now? This training page suggests they are needed only over ledgers attached to non-masonry.