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

    If execution is currently suspended at a routine call, STEP/INTO
    executes the program up to the beginning of that routine (steps
    into that routine). Otherwise, STEP/INTO has the same effect as
    STEP without a qualifier. The /INTO qualifier is the opposite of
    /OVER (the default behavior).

                                   NOTE

       On Alpha processors, when execution is stopped at an
       exception break, STEP/INTO does not transfer control to a
       user exception handler. Stop execution within the handler by
       setting a breakpoint in the handler.

    The STEP/INTO behavior can be changed by also using the /[NO]JSB,
    /[NO]SHARE, and /[NO]SYSTEM qualifiers.