Barcode: Difference between revisions

From MusicBrainz Wiki
Jump to navigationJump to search
mNo edit summary
No edit summary
Line 33: Line 33:
* The digit just before the checksum often stands for media type. E.g. many EMI sublabels often use these: 1 - LP, 2 - CD, 4 - MC, 6 - 12" vinyl, 7 - 7" vinyl, 8 - MD. If you have one barcode, you can try changing the type digit, recalculating the check digit and googling for the new barcode. But also note that different media types sometimes contain different track lists. E.g. LPs are sometimes shorter than CDs.
* The digit just before the checksum often stands for media type. E.g. many EMI sublabels often use these: 1 - LP, 2 - CD, 4 - MC, 6 - 12" vinyl, 7 - 7" vinyl, 8 - MD. If you have one barcode, you can try changing the type digit, recalculating the check digit and googling for the new barcode. But also note that different media types sometimes contain different track lists. E.g. LPs are sometimes shorter than CDs.
* If all you have is a catalog number, and you think it's part of a barcode, look for releases from the same years, artist and/or label with similar numbers. You'll often find many releases have the same barcode prefix, so all you'll have to do is prepend the prefix to the catalog number, add the type digit (if needed), calculate the check digit - and you're done.
* If all you have is a catalog number, and you think it's part of a barcode, look for releases from the same years, artist and/or label with similar numbers. You'll often find many releases have the same barcode prefix, so all you'll have to do is prepend the prefix to the catalog number, add the type digit (if needed), calculate the check digit - and you're done.

==Guidance==

I would like this page to include official guidance on the following topics:

* Whether physical packaging known to not have a barcode printed on the packaging should be marked "This release does not have a barcode". This would seem to be the primary reason for having this checkbox, and yet on one at least one occasion, I've received guidance that the barcode should be obtained from the Internet. If that is not what this checkbox is for, what is it for?
* Whether the check digit should be added when it is missing from the physical packaging. The most common guidance appears to be that it should be calculated, although I question the wisdom of entering data that does not match the physical product. In particular, it seems that the presence or absence of the check digit is useful in distinguishing between subtly different releases.
* The appropriate use of the "I confirm that this is the barcode as it appears on the release" check box. Is this only for situations in which the barcode is significantly non-standard? For cases where the check digit is missing? For cases where one or more digits are invalid?
* What to do when there's a barcode, but it has no printed digits. I suggest using a barcode scanner and entering that value.
* What to do when the printed digits and scanned value differ. While this is rare, I'm fairly certain it has occurred, at least on books in my collection.
* This might also be an appropriate place to at least link to what to do when the barcode has been replaced by other information. (e.g. BMG Direct Marketing releases).


==Other Identifiers==
==Other Identifiers==

Revision as of 18:17, 23 November 2013

Template:DocumentationHeader

Definition

Barcodes are machine-readable numbers used as stock control mechanisms by retailers: as such they are highly standardised and well recognised, and form an invaluable identifier for communication between companies.

There are many different types of barcode but the usual ones are Global Trade Item Numbers (GTINs). The most common types of GTIN are:

  • Universal Product Code (UPC), which is the original barcode used in North America. They are 12 digits long, but any number of zeros at the start can be left off, so the actual printed barcode can be shorter than this.
  • European Article Number (EAN) also known as Japanese Article Number (JAN), which is widely used in the rest of the world. The 13 digit type (EAN-13) is the most common, although there are others such as EAN-8. A UPC can be turned into an EAN-13 by adding a leading zero.

Reasons for Adding Barcodes

  • Barcodes are an industry standard for identifying products. Adding barcodes makes the MusicBrainz data much more accessible and useful for a variety of organisations, from wholesalers and retailers to public libraries. Some of them might be prepared to license the MusicBrainz database.
  • Barcodes are clear, visually distinct, well recognised, almost ubiquitous, and are generally unique to a specific release. This makes them a really useful way to help amateur cataloguers be precise about exactly what they are talking about, even if they don't understand the full subtleties of re-releases, regional variations, catalog numbers, and so on.
  • Using a barcode makes it easy to match a MusicBrainz release to an Amazon ASIN. This adds cover art to releases, and earns MusicBrainz money through referral fees.
  • USB barcode scanners are cheap and can be an easy way to manage large collections of music.

Finding

You're in luck if you have the physical media and there's a barcode printed on it. When doing research on releases you don't own, it's often hard to find the right UPC/EAN. Here are some tips to help you out.

Googling

  • "<artist name>" "<release name>" EAN/UPC/JAN
  • <Amazon ASIN> EAN/UPC/JAN
  • <catalog number> EAN/UPC/JAN

Guessing

  • Many western labels use parts of barcodes for catalog numbers, or rather catalog numbers in barcodes.
  • The last digit is always the checksum. You can easily calculate it using an on-line tool.
  • The digit just before the checksum often stands for media type. E.g. many EMI sublabels often use these: 1 - LP, 2 - CD, 4 - MC, 6 - 12" vinyl, 7 - 7" vinyl, 8 - MD. If you have one barcode, you can try changing the type digit, recalculating the check digit and googling for the new barcode. But also note that different media types sometimes contain different track lists. E.g. LPs are sometimes shorter than CDs.
  • If all you have is a catalog number, and you think it's part of a barcode, look for releases from the same years, artist and/or label with similar numbers. You'll often find many releases have the same barcode prefix, so all you'll have to do is prepend the prefix to the catalog number, add the type digit (if needed), calculate the check digit - and you're done.

Guidance

I would like this page to include official guidance on the following topics:

  • Whether physical packaging known to not have a barcode printed on the packaging should be marked "This release does not have a barcode". This would seem to be the primary reason for having this checkbox, and yet on one at least one occasion, I've received guidance that the barcode should be obtained from the Internet. If that is not what this checkbox is for, what is it for?
  • Whether the check digit should be added when it is missing from the physical packaging. The most common guidance appears to be that it should be calculated, although I question the wisdom of entering data that does not match the physical product. In particular, it seems that the presence or absence of the check digit is useful in distinguishing between subtly different releases.
  • The appropriate use of the "I confirm that this is the barcode as it appears on the release" check box. Is this only for situations in which the barcode is significantly non-standard? For cases where the check digit is missing? For cases where one or more digits are invalid?
  • What to do when there's a barcode, but it has no printed digits. I suggest using a barcode scanner and entering that value.
  • What to do when the printed digits and scanned value differ. While this is rare, I'm fairly certain it has occurred, at least on books in my collection.
  • This might also be an appropriate place to at least link to what to do when the barcode has been replaced by other information. (e.g. BMG Direct Marketing releases).

Other Identifiers

Also see http://www.iasa-web.org/icat/08_0.htm for some others.

Resources

List of country codes to find where an EAN comes from.

Retrieved from "https://wiki.musicbrainz.org/index.php?title=Barcode&oldid=65080"