In reply to tjin:
> But the question is about re-racking at belays, but the size are generally colour coded by the manufacture? Who has who's gear is for after the climbs...
http://people.bath.ac.uk/dac33/high/4Gear.htm#slingdraws - scroll up a tiny bit. The general idea is that you mark all your small wires in, say, yellow, and all your large wires in red. Second gets to the belay and can easily sort the rack out without having to properly look at each wire, and without having to know how you like things racked. I think it's a brilliant idea.
I didn't even think of tuff tags (despite being well aware of their existence) - but I do like the idea of a big, solid-coloured krab over a small stripe.