/sys$common/syshlp/helplib.hlb System Services, $SETPRN, Argument  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 prcnam

    OpenVMS usage:process_name
    type:         character-coded text string
    access:       read only
    mechanism:    by descriptor-fixed-length string descriptor
    Process name to be given to the calling process. The prcnam
    argument is the address of a character string descriptor pointing
    to a 1- to 15-character process name string. If you do not
    specify prcnam, the calling process is given no name.