DOI Applications > Use and Extension of the Resolution Functions

At the most basic level, all DOI applications query the DOI System by resolving a DOI name. The request can be structured to ask for all of the DOI record elements associated with that DOI name, or all of the elements of a specific type and/or index, etc. (see DOI Proxy Query Command Format). Applications are built to understand one or more of the element types, and parse, evaluate, and take action based on the corresponding element values.

The DOI record that is associated with a DOI name is stored in the DOI System in type/value pairs (see Introduction to the Handle Record). This is extremely flexible and open: new types can be added at any time, and the values can be of arbitrary complexity. Type/value pairs can be administrative (creation date, permissions, etc.), well known and standardized (URL, email, 10320/LOC, etc.), or created by a Registration Agency for a specific application purpose (for example, a custom type with a value that is binary data or a specially formatted string). There can be many type/value pairs associated with a DOI name, and multiples of the same type.

Associating XML, or other machine readable data with a DOI name, expands the utility of multiple resolution even further, adding features, and offering more options for negotiating content, and facilitating the creation of Linked Data applications.

NOTE New types should, but are not required to, be registered in the Handle System as Handles. As a general rule types containing a slash (for example, 10320/LOC) should be considered full Handles and those without a slash (for example, URL) should be assumed to be suffixes under the 0.TYPE prefix (with the previous example: 0.TYPE/URL). The type Handle Record may define the syntax, structure, possible semantics, or any other necessary descriptive characteristics of the corresponding value field. For more information, see the Digital Object Identifier Resolution Protocol (DO-IRP) Specification.