VMS Help CONVERT, file, Qualifiers, /MERGE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Specifies that records are to be inserted into their proper
    position in an existing indexed file.

    Format

      /MERGE

      /NOMERGE  (DEFAULT)

    The /MERGE qualifier is useful when your input records are not
    sorted and you do not want them to be sorted as they are loaded
    into an output file.

    If you specify both /MERGE and /CREATE, /MERGE overrides the
    /CREATE qualifier.