Library /sys$common/syshlp/dbg$help.hlb DEBUG, SET, TRACE, Qualifiers, /JSB  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /JSB
       /NOJSB

    (VAX only) Qualifies /INTO. Use with /INTO and one of the
    following qualifiers:

       /BRANCH
       /CALL
       /INSTRUCTION
       /INSTRUCTION=(opcode[, . . . ])
       /LINE
       /VECTOR_INSTRUCTION

    The /JSB qualifier is the default for all languages except DIBOL.
    It lets the debugger set tracepoints within routines that are
    called by the JSB or CALL instruction. The /NOJSB qualifier (the
    DIBOL default) specifies that tracepoints not be set within
    routines called by JSB instructions. In DIBOL, application-
    declared routines are called by the CALL instruction and DIBOL
    Run-Time Library routines are called by the JSB instruction.