Denys writes...
 
I was not aware of the +2 and +1, and I have yet to see
one, or even the space for it on a form.
 
Usually the DPBC (Delivery Point Bar Code) is generated automatically
by programs that decipher the address. Several are available on CIS
forums. I have one written in MS Access Basic. (Several versions,
actually) None I have seen decipher to obtain exactly what you get
when you send your DB to the USPO to get the Zip code and DPBC updates.
But I have found that the program will get them right about 99% of the
time.
 
If anyone is interested in this (and porting to whatever code they want)
let me know.
 
Elbert
 
p.s. The USPO has several books for free on this stuff. So you can make
your addresses perfect so the article gets to the recipient in a safe,
speedy manner -- sometimes.
Also, they do provide a free service (some limitations) for a person to
supply them with a mailing DB. They will scan it, update the ZIP and
ZIP+4 and provide the DPBC also. You then merge it back into your own DB.