What I found so far, please add anything that could simplify scripters life and is not in erm help actually. 
;If OB:T = 34 (hero). #get object under hero / erm snippet
;Fix day of, all erm help is wrong about:
; redraw town screen
;change battlefield during battle
;Mop function, find hero portrait for DL
;safe functions equip/delete artifact
;set scouting radius
;65000 objects allowed (XXL maps)
;pitlords summon horned demons
;DL addition:
Code:
A#1/#2/$/1    Change dialogue item characteristic.
#1 - item ID
#2    type    $
  3    Text    (string): new text of the item
  4    Def     (number): new cadre in Def
  11    Pcx     (string): new picture
 #4  parameter should always be 1 (anyone care to explain why?)
Notes:
May be called in !?DL trigger and so may be used to customize the dialog on a fly.