DOI stands for Digital Object Identifier. DOIs are what is known as “persistent identifiers” or PIDs. A DOI links persistently to a publication so that – provided it is kept up to date – any link or reference to it should take a user to where the article currently resides online. They are useful for citation metrics, but also as a way to prevent or combat dead links. They make content easier to locate.
[A DOI is] a unique alphanumeric string assigned to a digital object – in this case, an electronic journal article or a book chapter. In the Crossref system, each DOI is associated with a set of basic metadata and a URL pointer to the full text, so that it uniquely identifies the content item and provides a persistent link to its location on the internet.
For more information on the DOI itself, which is a NISO standard syntax, please visit the International DOI Foundation website at www.doi.org. For details on the use of the DOI within Crossref, please see the “How Crossref Works” page.
See more at http://www.crossref.org/about/
The key to this statement is that a DOI is unique. Any article should only have one unique combination of a DOI prefix and suffix. Articles should also, ideally, only have one DOI each.
To use DOIs for your publication, you’ll need to meet the following requirements:
Let’s break these steps down one by one.
One Issue of your journal must be published – You’ll need to have one existing issue of your journal to acquire a Crossref membership. However, you’ll also need an ISSN and, as luck would have it, having a published issue is a requirement for an ISSN as well.
An ISSN must be assigned to your journal – Once you’ve published an issue, you can apply for an ISSN. ISSNs are identifiers used to distinguish and locate specific journal titles. You can find out more about acquiring an ISSN at issn.org.
Registering with a DOI Registration Agency – Creating/”minting” a DOI is easy. However, for that DOI to be useful, it has to be registered through an agency who manages the linking service and handle metadata exchanges. This guide is specific to Crossref, but there are other DOI services available such as Datacite and mEDRA (you can see a list of approved agencies at doi.org).