anchor.diff:  
   == Direction Parameters
   
  -Direction parameters are a way to tell a group of fixtures to point in a
  -particular direction, or move in unison or in a coordinated pattern. The
  -basic way to create one is to call:
  +Direction parameters are a way to tell a group of fixtures to point in
  +a particular direction, or move in unison or in a coordinated pattern.
  +They are used with <<effects#direction-effects,Direction Effects>>.
  +The basic way to create one is to call:
   
   [source,clojure]
   ----
  
positive.code: nor right, neither up nor down, and straight towards the audience.
  `[1, 0, 0]` would be straight right, `[-1, 0, 0]` straight left, `[0,
  1, 0]` straight up, and `[0, 1, -1]` up and away from the audience at
  a 45° angle.
  
  All of these parameters, except for `frame-dynamic`, can themselves be
  dynamic parameters, such as show <<variable-parameters,variables>>
  
negative.code: 
  Aim parameters are a way to tell a group of fixtures to aim at a
  particular point in space, or track something in unison or in a
  coordinated pattern. They are used with <<effects#aim-effects,Aim
  Effects>>. The basic way to create one is to call:
  
  [source,clojure]
  ----
  