Access Constraints

The <Access_Constraints> field allows the author to provide information about any constraints for accessing the data set.  This includes any special restrictions, legal prerequisites, limitations and/or warnings on obtaining the data set.  Some words that may be used in this field include: Public, In-house, Limited, Additional detailed instructions on how to access the data can be entered in this field.


  • Multiple lines of text are permitted. Characters may be selected from the UTF-8 character set.
  • The <Access_Constraints> field is highly recommended and may not be repeated.
  • Text should be single spaced with blank lines separating paragraphs.


<Access_Constraints>Registration is required to access the data.</Access_Constraints>


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