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

       /CONTIGUOUS
       /NOCONTIGUOUS

    Specifies that the output file must occupy physically contiguous
    disk blocks. By default, the APPEND command creates an output
    file in the same format as the corresponding input file and does
    not report an error if not enough space exists for a contiguous
    allocation. This qualifier is relevant only with the /NEW_VERSION
    qualifier.

    If an input file is contiguous, the APPEND command attempts to
    create a contiguous output file, but does not report an error if
    there is not enough space. If you append multiple input files of
    different formats, the output file may or may not be contiguous.
    Use the /CONTIGUOUS qualifier to ensure that the output file is
    contiguous.