Library /sys$common/syshlp/nclhelp.hlb set, session_control, application, maximum instances (Tru64 UNIX)  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Default: 0

    Maximum number of simultaneous instances of this application
    allowed. If a connect request comes in for this application
    while the maximum number of instances exist, the connect request
    will be rejected with ObjectTooBusy. A value of 0 indicates no
    maximum.