Editing Universal Product Code (section)

=== UPC-E ===
To allow the use of UPC barcodes on smaller packages, where a full 12-digit barcode may not fit, a zero-suppressed  version of UPC was developed, called UPC-E, in which the number system digit, all trailing zeros in the manufacturer code, and all leading zeros in the product code, are suppressed (omitted).<ref>{{cite web|title=UPC-A Symbology – UPC-E background information and UPC-A to UPC-E conversion|url=http://www.barcodeisland.com/upce.phtml|website=barcodeisland.com|access-date=21 January 2013|archive-date=26 February 2020|archive-url=https://web.archive.org/web/20200226110541/http://www.barcodeisland.com/upce.phtml|url-status=dead}}</ref> This symbology differs from UPC-A in that it only uses a 6-digit code, does not use M (middle) guard pattern, and the E (end) guard pattern is formed as ''space-bar-space-bar-space-bar'', i.e. UPC-E barcode follows the pattern SDDDDDDE. The way in which a 6-digit UPC-E relates to a 12-digit UPC-A, is determined by UPC-E numerical pattern and UPC-E parity pattern. It can only correspond to UPC-A number system 0 or 1, the value of which, along with the UPC-A check digit, determines the UPC-E parity pattern of the encoding. With the manufacturer code digits represented by M's, and product code digits by P's, then:

{| class="wikitable" style="text-align:center;"
! Last UPC-E digit !! UPC-E numerical pattern !! UPC-A equivalent !! Available product numbers
|-
| 0 || style="font-family:monospace;" | MMPPP0 || style="font-family:monospace;" | 0 or 1 + MM000-00PPP + check digit || style="font-family:monospace;" | PPP = 000-999
|-
| 1 || style="font-family:monospace;" | MMPPP1 || style="font-family:monospace;" | 0 or 1 + MM100-00PPP + check digit || style="font-family:monospace;" | PPP = 000-999
|-
| 2 || style="font-family:monospace;" | MMPPP2 || style="font-family:monospace;" | 0 or 1 + MM200-00PPP + check digit || style="font-family:monospace;" | PPP = 000-999
|-
| 3 || style="font-family:monospace;" | MMMPP3 || style="font-family:monospace;" | 0 or 1 + MMM00-000PP + check digit || style="font-family:monospace;" | PP = 00-99
|-
| 4 || style="font-family:monospace;" | MMMMP4 || style="font-family:monospace;" | 0 or 1 + MMMM0-0000P + check digit || style="font-family:monospace;" | P = 0-9
|-
| 5 || style="font-family:monospace;" | MMMMM5 || style="font-family:monospace;" | 0 or 1 + MMMMM-00005 + check digit || style="font-family:monospace;" | 5 = P
|-
| 6 || style="font-family:monospace;" | MMMMM6 || style="font-family:monospace;" | 0 or 1 + MMMMM-00006 + check digit || style="font-family:monospace;" | 6 = P
|-
| 7 || style="font-family:monospace;" | MMMMM7 || style="font-family:monospace;" | 0 or 1 + MMMMM-00007 + check digit || style="font-family:monospace;" | 7 = P
|-
| 8 || style="font-family:monospace;" | MMMMM8 || style="font-family:monospace;" | 0 or 1 + MMMMM-00008 + check digit || style="font-family:monospace;" | 8 = P
|-
| 9 || style="font-family:monospace;" | MMMMM9 || style="font-family:monospace;" | 0 or 1 + MMMMM-00009 + check digit || style="font-family:monospace;" | 9 = P
|}

For example, a UPC-E 654321 may correspond to the UPC-A 065100004327 or 165100004324, depending on the UPC-E parity pattern of the encoded digits, as described next:

{| class="wikitable" style="text-align:center;"
! UPC-A <br />check digit 
! UPC-E parity pattern for UPC-A<br />
number system 0
! UPC-E parity pattern for UPC-A<br />
number system 1
|-
| 0 || style="font-family:monospace;" | EEEOOO || style="font-family:monospace;" | OOOEEE
|-
| 1 || style="font-family:monospace;" | EEOEOO || style="font-family:monospace;" | OOEOEE
|-
| 2 || style="font-family:monospace;" | EEOOEO || style="font-family:monospace;" | OOEEOE
|-
| 3 || style="font-family:monospace;" | EEOOOE || style="font-family:monospace;" | OOEEEO
|-
| 4 || style="font-family:monospace;" | EOEEOO || style="font-family:monospace;" | OEOOEE
|-
| 5 || style="font-family:monospace;" | EOOEEO || style="font-family:monospace;" | OEEOOE
|-
| 6 || style="font-family:monospace;" | EOOOEE || style="font-family:monospace;" | OEEEOO
|-
| 7 || style="font-family:monospace;" | EOEOEO || style="font-family:monospace;" | OEOEOE
|-
| 8 || style="font-family:monospace;" | EOEOOE || style="font-family:monospace;" | OEOEEO
|-
| 9 || style="font-family:monospace;" | EOOEOE || style="font-family:monospace;" | OEEOEO
|}

{| class="wikitable" style="text-align:center; background-color:#80A080;"
|+ Encoding table for UPC-E barcode pattern SDDDDDDE
! rowspan="2" | S<br/>(start)
! colspan="10" | O<br/>(odd parity digit)
! colspan="10" | E<br/>(even parity digit)
! rowspan="2" | E<br/>(end)
|-
! 0 !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7 !! 8 !! 9 !! 0 !! 1 !! 2 !! 3 !! 4 !! 5 !! 6 !! 7 !! 8 !! 9
|- valign="top"
| [[File:UPC-E S.svg|10x250px]] || style="font-size:70%;" | [[File:UPC-E 0ow.svg|21x235px]]<br />3-2-1-1 || style="font-size:70%;" | [[File:UPC-E 1ow.svg|21x235px]]<br />2-2-2-1 || style="font-size:70%;" | [[File:UPC-E 2ow.svg|21x235px]]<br />2-1-2-2 || style="font-size:70%;" | [[File:UPC-E 3ow.svg|21x235px]]<br />1-4-1-1 || style="font-size:70%;" | [[File:UPC-E 4ow.svg|21x235px]]<br />1-1-3-2 || style="font-size:70%;" | [[File:UPC-E 5ow.svg|21x235px]]<br />1-2-3-1 || style="font-size:70%;" | [[File:UPC-E 6ow.svg|21x235px]]<br />1-1-1-4 || style="font-size:70%;" | [[File:UPC-E 7ow.svg|21x235px]]<br />1-3-1-2 || style="font-size:70%;" | [[File:UPC-E 8ow.svg|21x235px]]<br />1-2-1-3 || style="font-size:70%;" | [[File:UPC-E 9ow.svg|21x235px]]<br />3-1-1-2 || style="font-size:70%;" | [[File:UPC-E 0ew.svg|21x235px]]<br />1-1-2-3 || style="font-size:70%;" | [[File:UPC-E 1ew.svg|21x235px]]<br />1-2-2-2 || style="font-size:70%;" | [[File:UPC-E 2ew.svg|21x235px]]<br />2-2-1-2 || style="font-size:70%;" | [[File:UPC-E 3ew.svg|21x235px]]<br />1-1-4-1 || style="font-size:70%;" | [[File:UPC-E 4ew.svg|21x235px]]<br />2-3-1-1 || style="font-size:70%;" | [[File:UPC-E 5ew.svg|21x235px]]<br />1-3-2-1 || style="font-size:70%;" | [[File:UPC-E 6ew.svg|21x235px]]<br />4-1-1-1 || style="font-size:70%;" | [[File:UPC-E 7ew.svg|21x235px]]<br />2-1-3-1 || style="font-size:70%;" | [[File:UPC-E 8ew.svg|21x235px]]<br />3-1-2-1 || style="font-size:70%;" | [[File:UPC-E 9ew.svg|21x235px]]<br />2-1-1-3 || style="font-size:70%;" | [[File:UPC-E E.svg|18x250px]]
|}

UPC-E 654321 with "EOEOEO" parity pattern (UPC-A 065100004327) would be encoded as

:1-1-1 &nbsp;4-1-1-1 &nbsp;1-2-3-1 &nbsp;2-3-1-1 &nbsp;1-4-1-1 &nbsp;2-2-1-2 &nbsp;2-2-2-1 &nbsp;1-1-1-1-1-1.

The barcode would look like this: 
[[File:UPC-E-654321.png|center]]