|— The original 1959 dry toner Xerox —|
COPIERS USED TO BE ANALOG, now they are digital. Faster, better, cheaper. Well, ARS TECHNICA has an interesting report, “Confused photocopiers randomly rewriting scanned documents” that shows that sometimes, you might not get copies that are identical to the original.
Photocopiers exist to produce close enough replicas of original documents. Traditionally, they just spit out the result onto paper. Most copiers these days can operate as (generally rather large) scanners, generating PDFs, TIFFs, or other electronic representations. But some Xerox copiers have recently been found to produce scans that, well, aren't that close to the originals at all. The copiers are producing documents that look superficially similar to the originals but switch around numbers apparently at random.
Now, numbers are important, so do check your copies — or you might wish you had.