Punching a sequence number in columns 73-80 was not practical. Even if you allowed increments of 10 or 100, there always arose a situation where you had to inse

Punching a sequence number in columns 73-80 was not practical. Even if you allowed increments of 10 or 100, there always arose a situation where you had to insert more cards between two existing cards, than there was room. Ex: insert eleven statements between card 1230 and 1240. Plus, you would have to manually enter the sequence numbers of the new cards, waaaay over in column 73, which was really slow and tedious on a card punch. Especially when you were in a rush because you were granted a brief slice of time on the computer, which was not capable of multiprogramming. You could always duplicate the deck and re-sequence from scratch, but that was done on a machine that did not print (interpret) the characters at the top, making it impossible to read and manually maintain the deck. The solution was: just don't drop the cards. I wrote and maintained a 4,000-card assembler program on a Univac 9300 in the 70's, and I never dropped my cards. The program was stored in two 16" metal trays.