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

    Performs the operation on the permanent affinity or capability
    mask as well as the current mask, making the changes valid for
    the life of the kernel thread. (The default behavior is to affect
    the current mask only for the running image.) The /PERMANENT
    qualifier is only valid in conjunction with the /CAPABILITY or
    the /AFFINITY qualifier.