Library /sys$common/syshlp/dbg$uihelp.hlb DEBUGUI, custm_db_hlp  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Use the Customize Button Dialog box to modify, add, remove, or
  resequence push buttons and the associated debugger commands.

  NOTE:  You cannot modify or remove the Stop push button.