Can someone tell me what is the proper way of annotating when sending xerox copies of a letter to others. For example "cc:" or "xc:". Is "xc" the proper way of annotating if indeed the copies are xerox copies, or is "cc" the proper way for all types.
I've never seen that before, to avoid confusion you probably should just stick to 'cc'.

also Cc at the end of a letter?
This is the first time I've heard of xc:
Maybe it is Xerox pushing this....doing a bit of branding.
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I work at an architecture firm and they use it all the time. Unfortunately i dont know why. It seems to be the same as CC.
cc is carbon copy and xc is xerox or email from a xerox machine
Back in the days everything was done carbon copy, hence "cc:"  now they are xerox copies so "xc:" is used to annotating that it is a xerox copy.
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I have still never seen "xc" on anything, and find it surprising, since Xerox is a brand name and there are several types of copiers. Should there be Cc for copies made on a Cannon copier, and Mc for those made on a Minolta copier?

I would suggest not using this. If you don't like to think of "carbon" then think of the "copier" so that you receive a copy that came off the photocopier.

I'm also locking this thread, since the one that Hitch linked to above is far more comprehensive, though there's a shocking number of people who can't resist saying the same thing that other people have already said before, ad nauseum.