Anyone out there know schematics??

Looking for someone very familiar with drawings, schematics, etc. I am looking to see what you do with the change box of the drawing when the changes become many and your down into a lot of revisions. I've had engineers here at my company tell me that you drop off the oldest rev changes and move the whole change box up keeing the newest changes (i.e. - delete the Rev A, B changes, etc and move up Rev C, D, etc to the top of the change box) , but in my mind (and the mind of the other engineers I've talked to) that's death with a drawing because you've lost a part of it's change history by doing that.
When your change box grows and grows and your into like rev J, M, etc. How do you keep it from taking over the entire drawing???
(I've got a real messy one on my hands right now and am running out of room)

I know with aviation drawings I deal with, they usually break off the first 10 or so into a separate box and stick it somewhere in a corner on the print. We make some of our own, but don't get into that many revisions.