Updates to Directory Interchange Format (DIF) Standard
This document describes modifications to the Directory Interchange Format (DIF) according to International Directory Network (IDN) Version 9.8.2 Release Notes, October 2010. NASA's Global Change Master Directory (GCMD) is an implementation of the DIF.
This document has been superseded by the DIF 10 specification as of August, 2016.
The Updates to DIF Standard is an approved standard recommemded for use in NASA Earth Science Data Systems (ESDS) in October 2010.
NASA Earth Science Community Recommendations for Use
ESDS-RFC-023 documents recent changes to the DIF schema, intended to enhance interoperability with the Federal Geographic Data Committee (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM) and the International Organisation for Standardisation (ISO) 19115 metadata standards. The DIF itself is already a NASA-endorsed metadata standard (ESDS-RFC-012). Earth Science community comments were all positive. Said one, "This RFC will clearly help integrating data management systems and should be endorsed."
One commenter notes a perceived weakness: “It looks like, in this community, the separation of purpose out of an abstract is standard. But in normal usage, abstract may likely include purpose.” However, the separate abstract and purpose fields were created specifically to conform to FGDC and ISO metadata specifications.
As NASA Earth Science Data Systems (ESDS) move toward adopting ISO metadata standards, closer alignment of our existing metadata standards is welcome. In the words of another commenter, “There will never be only one way of addressing the interoperability issue and DIF has a clear advantage in that it is lightweight and easy to implement and benefit from contrary to ISO standards.”
Additional DIF schema changes, beyond the two documented here, will be needed for full ISO compatibility.
Overall, reviewers were pleased with the updates to the DIF schema, and found that the RFC documentation was clear and helpful: “For these minor changes an endorsement is a no-brainer.”
Last Updated: Oct 16, 2019 at 2:40 PM EDT