The following example shows how to ask for a list of the help
       that is available:

       DTR> HELP

       The following example shows how to ask for help on the screen-
       oriented Help facility:

       DTR> HELP VIDEO

       The following example shows how to ask for help on the last error
       message you received. For example, if you use the SORT statement
       without first forming a collection, DEC DATATRIEVE displays an
       error message:

       DTR> READY YACHTS
       DTR> SORT BY LOA
       No collection for sort.

       You can issue the HELP ERROR command to find out the reason for
       the error message, possible actions to correct the error, and how
       to obtain more on-line information:

       DTR> HELP ERROR
       No collection for sort.

       ERROR_MESSAGES

       Errors

       NOCOLSOR

          008D8352 No collection for sort.

          Explanation:

          You can use the SORT statement only with an established
          collection.

          User Action:

          Use the SORTED BY clause in an RSE to order records not
          contained in an established collection. For example:
          PRINT EMPLOYEES SORTED BY LAST_NAME.

          You can also use the SORTED BY clause in the RSE of the FIND
          statement to order records when a collection is being created.
          In addition, you can use a SORT statement to reorder records
          after the collection is created.