Library /sys$common/syshlp/tracehlp.hlb SHOW, TRACE_COLLECTOR, process-name-string  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Process-name-string is  a  string  which  is  matched  against  the
    process  names  that  are  running  TRACE.  A match occurs with all
    TRACE processes that  begin  with  process-name-string.   '*'  will
    match all TRACE processes.

    If  you  omit  process-name-string  from  the  command,  all  trace
    collecting processes are displayed.