Digital Object Identifier - DOIs

System, appointing service providers for the System, and overseeing the successful
operation of the System.
Registration agency [DOI registration agency]
One of the agencies appointed by the International DOI Foundation to register and
allocate DOI prefixes to registrants, and which subsequently registers all DOIs issued by
the registrant using the prefix. A registration agency uses the Directory and provides the
information entered into the Directory. The Registration Agency may also be the
Directory Manager in certain cases.
Registrant
An organization or entity which has requested and been allocated a DOI prefix by a
Registration Agency and which subsequently allocates DOIs (constructed using that
prefix) to items of intellectual property and registers these in the Directory, with the
permission of, or via, the Registration Agency.
Registration
The act of entering into the Directory a DOI and associated information necessary for the
DOI to be used.
4. Format and Characteristics of the DOI
The DOI is made up of the Prefix and the Suffix. Within the prefix are the Directory
and the Registrant Prefix . The suffix is made up of the DOI Suffix String . The
allowed value of the DOI is a maximum of 128 characters.
The syntax of the DOI string is:
. /
Detailed explanations of each section of the DOI string follow.
4.1 Prefix
- Directory (required, numeric, two digits) –
The current value of is “10”. This is currently the only allowed value. In future, other
numbers may be assigned with the approval of NISO. The Maintenance Agency for this
standard should be contacted regarding other values.
Registrant’s Prefix (required, numeric, no limit)
Separated from by “.” and no spaces. This is the number assigned to the registrant by
the Registration Agency.
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