Announcement: The operation of NSDL has been transferred to ISKME's OER Commons (effective December, 2014) - Read the news release.
This documentation describes the policies, procedures, and services that existed while NSDL was operated by UCAR.
All resources in NSDL are assigned a unique, global, persistent identifier registered through the Handle System. The Handle System provides a means for resolving NSDL identifiers to their resident URL at NSDL using a DOI resolution service such as http://dx.doi.org/2200/20120201095822279T.
NSDL identifiers have a handle prefix of 2200, for example 2200/20120201095822279T.