Extended Metadata


The <Extended_Metadata> field stores user defined values within the metadata record without reusing existing GCMD defined metadata fields.

  • The <Extended_Metadata> field is optional and may not be repeated.
  • The <Metadata> field can be repeated.
  • If the <Metadata> field is used, the <Name> field is required.
  • The <Group> field can use a unique name for an organization and a reverse URL scheme is recommended. May contain up to 1024 characters.
  • If a <Group> field is not provided, then it will be assumed to be in an "uncategorized" group. Internally GCMD software will treat an undefined group as "*".
  • The <Name> field may contain up to 1024 characters.
    • <Name> fields must be unique in the global group. If two organizations use the same <Name> field for different usages, one must define their property within the <Group> field.
  • <Description> field is optional and is the description of the name-value (name).
  • <Type> field is optional and the mimetype of the name-value.
  • <Update_Date> field is optional and only supplied by the software if a variable has been updated.
  • The <Value> field and <Group> field are highly recommended and may contain binary data within a <![CDATA [ ] ]> tag.
  • The <Value> field is optional and assumed to be "yes".

<Value>2012-11-15 12:08:24</Value>


<Name>NASA Tag</Name>
<Description>NASA Tag for metadata subset</Description>
<Value>NASA EOSDIS</Value>


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