Brain-blowout. Sorry. An ALTER_TRANS that could do that is called REPLACE... should have reread the docs.
TRIGGER: The trigger condition for the transition. i.e "TRIGGER" ~Global("foo","GLOBAL",0)~
ACTION: The action performed if the transition is selected. i.e. "ACTION" ~SetGlobal("foo","GLOBAL",1)~
REPLY: The player’s reply, if any. i.e. "REPLY" ~REPLY #57922~
JOURNAL: Can add or change the journal entry. i.e. "JOURNAL" ~JOURNAL @100~
SOLVED_JOURNAL: Same as JOURNAL, except for entries into the solved section of the journal.
UNSOLVED_JOURNAL: Same as JOURNAL, except for entries into the unsolved section of the journal.
EPILOGUE: Specifies where the transition leads to (GOTO, EXTERN, or EXIT) i.e. EPILOGUE" ~EXTERN BVICONI 0~
FLAGS: Used to set transition flags manually, though I can’t imagine why one would do this.