Received mail from the US Postal Service can contain a fluorescent
barcode on the backside.  What is the content contained within this
barcode, and how does one go about decoding it?

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Request for Question Clarification by pafalafa-ga on 16 Feb 2005 08:35 PST

The barcodes on a piece of USPS mail generally encode one of three things:


--a five-digit ZIP Code, which is 32 bars in length

--a nine-digit ZIP+4 code, 52 bars long 

--or what USPS calls a "delivery point code" (often a specific
building) which is 62 bars long.


Can you let me know if the code you are looking at fits one of these
descriptions (32, 52 or 62 bars).  If so, I will try to find the
appropriate decoding information for you.

Thanks.


pafalafa-ga

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Clarification of Question by generica-ga on 16 Feb 2005 08:47 PST

I'm not talking about the codes described here:  http://bulkmail.info/barcode.html

On the back side of delivered mail, you get these fluorescent bars
that look very much like this, in bright orange ink, with 2mm gaps
between each bar:

| | | || || ||||||||||  |||   |||||   |||||||||| || |  |||   |

(And yes, that's an actual transliteration.)

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Request for Question Clarification by hammer-ga on 16 Feb 2005 10:48 PST

Generica,

The barcode you describe is sprayed onto the piece of mail when the
automated sorting equipment cannot decipher the address. It is an
internal identifier for the piece that corresponds to an image of the
address that a human will read to assign the correct ZIP. The code
does contain other purely internal information such as the machine
number and timestamp.

I found a newsgroup thread which describes how to decode these
barcodes, however, since the information contained in the barcode does
not appear to be generally useful, I wanted to check with you before
posting an official answer.  I called USPS, and they confirm that it
is just an internal sorting code.

Please let me know if this information is of value to you and
acceptable as an answer to your question.

- Hammer

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Clarification of Question by generica-ga on 16 Feb 2005 10:59 PST

It would be partially useful to decode the timestamp, and completely
useful to have some way of learning the location of the numbered
machine.  But what I asked for was just a content dumping mechanism,
and I'm not going to add conditions on top of that :)

If you _do_ get the location, I'll happily tip you for your troubles.

Generica,

The barcode you describe is sprayed onto the piece of mail when the
automated sorting equipment cannot decipher the address. It is an
internal identifier for the piece that corresponds to an image of the
address that a human will read to assign the correct ZIP. The code
does contain other purely internal information such as the machine
number and timestamp.

A general description of these barcodes can be found at the link below.
USPS Press Release
http://www.usps.com/news/2001/press/pr01_002.htm

Specific information on the contents and structure of this barcode are
avaialble scattered through the following newsgroup thread. Below the
link, I've extracted some of the most relevant portions of the thread,
although the thread is interesting and worth looking through.
http://groups-beta.google.com/group/alt.snail-mail/browse_frm/thread/8b88c6ea72175777/a11181fe72896c5e?q=post+%22bar+code%22+orange+sort&_done=%2Fgroups%3Fq%3Dpost+%22bar+code%22+orange+sort%26ie%3Dutf8%26oe%3Dutf8%26sourceid%3Dmozilla-xul%26&_doneTitle=Back+to+Search&&d#a11181fe72896c5e

--------------------------------------------------------- 	
my2cents 	  Jun 28 2004, 9:03 am     show options
Newsgroups: alt.snail-mail
From: (my2cents) - Find messages by this author
Date: 28 Jun 2004 09:03:13 -0700
Local: Mon, Jun 28 2004 9:03 am
Subject: Re: orange bar code

Zhang,

Did a little more detective work. I was wrong about the type of
barcode. It does use 1s and spaces to represent numerals. It is sort
of a reverse barcode. The space is the numeric marker. It's hex except
for #7. (don't ask me) Here is a breakdown of the #s:

0 - 1111
1 - 111
2 - 11 1
3 - 11
4 - 1 11
5 - 1 1
6 - 1  1
7 -  1
8 -  111
9 -  11 
--------------------------------------------------------- 

 	
my2cents 	  Jun 23 2004, 6:30 am     show options
Newsgroups: alt.snail-mail
From: (my2cents) - Find messages by this author
Date: 23 Jun 2004 06:30:46 -0700
Local: Wed, Jun 23 2004 6:30 am
Subject: Re: orange bar code

The ID tag (image record descriptor) is made of the following information.
Machine ID - 4 digit # that relates to the image lift equipment and plant
Mailpiece # - 1 to 24999
Time stamp - in 1/2 hour increments
Date
and lastly, mail class

Unfortunately, there is no simple decode process as with postnet barcodes. 
----------------------------------------------------

It is possible that the Machine ID can be resolved to a particular
location, however, I doubt if such a list is publicly available and/or
kept publicly current and complete. I'll take a look, but I'm not
optimistic about finding such a thing.

Best regards,

- Hammer

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Clarification of Answer by hammer-ga on 16 Feb 2005 13:48 PST

Generica,

I forgot to attach my search strategy to the answer.

Search Strategy
----------------
Google Web and Google Groups searches
USPS "bar code" orange

- Hammer

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Clarification of Answer by hammer-ga on 17 Feb 2005 08:54 PST

Generica,

Do you want the location of the machine for one particular barcode, or
do you want to be able to lookup the location of any machine id you
receive?

- Hammer

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Request for Answer Clarification by generica-ga on 18 Feb 2005 11:52 PST

One particular barcode if you can manage.  You'll be tipped beyond the
price of the answer if you can find the information.  Is it possible
for us to continue this discussion offline?

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Clarification of Answer by hammer-ga on 18 Feb 2005 12:09 PST

We are not permitted to have contact with Customers outside of Google Answers.

I'm willing to try to track down this information, but I will need
your particular barcode. Is it the one you posted above? If so, are
you sure you've got it exactly right? If you're not sure, you may want
to decode it using the table in my answer and give me the decoded
numbers.

- Hammer

generica,

 the info you requested about this idtag is machine 1940 san francisco, processed
on the eleventh of that month at 21:30 (9:30 pm). hope this helps.