anchor.diff:  
   ==== Chains
   
  -A chain layer includes both, span and relation annotations into a single structural layer. Creating
  -a span annotation in a chain layer basically creates a chain of length one. Creating a relation 
  +A chain layer includes both, span and relation annotations, into a single structural layer. Creating
  +a span annotation in a chain layer basically creates a chain of length one. Creating a relation
   between two chain elements has different effects depending on whether the *linked list* behavior
   is enabled for the chain layer or not.
   
  
positive.code: ==== Relations
  
  To create a relation annotation, click on a span annotation and drag the mouse to another span
  annotation. While you drag, an arc is drawn. It is not possible to create arbitrary relation 
  annotations. In order to create one, a corresponding relation layer needs to be defined between
  the source and target spans.
  
  To abort the creation of an annotation, hold *CTRL* when you release the mouse button.
  
  Depending on the layer behavior configuration, relation annotations can stack, can cross each other,
  cross sentence boundaries. 
  
  NOTE: Currently, there can be at most one relation layer per span layer. Relations between spans
        of different layers are not supported.
  
  NOTE: A special behavior for the built-in *Dependency* layer is the handling of the dependency 
        root. To mark a token as the *ROOT* of the dependency tree, create a dependency relation from
        the POS tag to itself (a circle). This behavior is not active for custom relation layers!
  
  
negative.code: by the current user, blue font means that it has already been opened, whereas red font indicates 
  that the document has already been marked as *done*.
  
  Once the document is opened, a default of 10 sentences is loaded on the annotation  page.  The  
  *Settings*  button will  allow  you  to specify the settings of the annotation layer.
  
  The first option allows you to select an annotation layer which is displayed during annotation. The second option allows you to specify the number of sentences that will be displayed on one page. The last option allows you to select auto-scroll while annotating. Auto-scroll scrolls automatically forward by putting the last annotated sentence in the middle.
  
  === Navigation
  
  Sentence  numbers  on  the  left  side  of  the  annotation  page  show  the  exact sentence numbers in the document. 
  
  image::annotation3.jpg[align="center"]
  
  