Minecraft wiki entry for Flattening, associated text: /clear [<data>] argument removed.[command note 1]
/clone [<data>] argument merged with ID and no longer allows metadata.[command note 2]
/execute detect (now /execute if|unless block) [<data>] argument merged with ID and no longer allows metadata.[command note 2]
/fill [<data>] and [<replaceData>] arguments merged with ID and no longer allow metadata.[command note 2]
/give [<data>] argument removed.[command note 1]
/replaceitem [<data>] argument removed.[command note 1]
/setblock [<data>] argument merged with ID and no longer allows metadata.[command note 2]
/particle [<params>] arguments merged with name and formatted as block_id[states] and item_id.