VMS Help INSTALL, DELETE, Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The DELETE command deletes an entry from the known file list. The
    image's entry on the known file list and any global sections
    created for the image are deleted. The image file remains
    unaffected. Writable global sections are written back to disk
    upon their removal as known images.

    If a process is accessing global sections when the DELETE command
    is entered, the global sections are deleted only after the
    operation initiated by the process completes. However, once the
    command is entered, no additional processes can access the global
    sections because they are marked for deletion.