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A couple things to note: The Barcode Clear Zone is exactly that, a clear zone. No text or graphics can be in this 4.75" by 0.625" area. Also, in the OCR Read Area, OCR stands for Optical Character Recognition, a machine operated sorting process. Robots score another point against the humans. Nothing but essential addressee information should appear in this area.
In addition, the US Postal Service has a website with all of it's guidelines, but the user interface and information architecture is down right atrocious. It's close to impossible to find anything especially if you don't speak "mail". Most everything has a specific term so nothing is easily searchable. How would someone guess that this information is in the "DMM 102 Elements on the Face of a Mailpiece" page? Their "Postal Explorer" needs a much overdue major overhaul. Good luck to the people who take on that task.