Thanks for this link. I've looked it over before but wasn't confident that the section 7 regarding ladders was all inclusive. They basically just say follow other applicable safety behaviors as you would on the ground plus follow the manufacturer guidelines. I'm satisfied with that unless someone else posts additional info. I guess I was expecting a more specific/lengthy standard.http://www.isa-arbor.com/resources/2012_ANSI_Z133_Standard_Second_Public_Review.pdf This is the draft version the ANSI Committee put out for review last year, it's not a final document, but it might help you with your research.