Confetiur. Collegial lawyers don't send each other pdf's. They are impossible to mark up. One "innovation" I have seen is with banks. They do not want their employees to be creative; edge cases don't exist, everything is binary. So the banks issue grids/tables containing a list of questions. The answers are found in the corresponding place on the table. Imagine 7 columns, all containing binary answers: "yes" or "no." Except, everything is not binary. So the 8th column contains, I dunno, 500 words, a minitable, etc., running over page after page. The other columns on these runover pages are blank. And these are all pdf's.