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Entry Identifier

The <Entry_ID> is the unique document identifier of the metadata record. The <Entry_ID> is determined by the metadata author or data center contact personnel and may be identical to identifiers used by the data provider’s data center or organization. For example, the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) identifies their metadata records as NSIDC-xxxx, where xxxx is a numerical designator. Also, the identifier is case insensitive meaning nsidc-xxxx and NSIDC-xxx refer to the same metadata record.
<Entry_ID> text entry identifier </Entry_ID>
  • The <Entry_ID> consists of 1 to 80 alphanumeric characters of the UTF-8 set, including underbar (_), hyphen (-) and period (.)
  • The following characters are not allowed in the <Entry_ID>:
    • Backward Slash ( \ )
    • Forward Slash (/ )
    • Colon ( : )
    • Spaces ( )
  • The <Entry_ID> is required and is not repeatable.


The following would not be allowed:
<Entry_ID>NSIDC23/5</Entry_ID>.The forward slash (/) is not an allowed character.


This document should be cited as:
Directory Interchange Format (DIF) Writer's Guide, 2018.
Global Change Master Directory.
National Aeronautics and Space Administration.

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