anchor.diff:  == Document ids and the reference graph
   
   NOTE: This is a non-standard extension of asciidoc. If you use this feature, you will
  -need to generate your documents using giblish to make this work.
  +need to generate your documents using giblish to make this work as intended.
   
   giblish extends the cross reference concept in asciidoc with a _document id_ mechanism.
   To use this, you need to:
   
  - . Add a `:docid:` entry in your document's header section.
  + . Add a `:docid:` entry in your document's header section. The doc id can consist of
  +   up to 10 characters and must be unique within the set of documents generated by
  +   giblish.
    . Refer to a document using the syntax pass:[<<:docid:#DOC_ID#>>].
    . Run giblish with the -d switch when generating documents.
   
  
positive.code:    are clearly seen (this feature require that the 'dot' tool, part of the graphwiz package
     is installed on the machine where giblish is run).
  
  === Example of using the docid feature
  
  Example document one::
  
  
negative.code: = giblish
  :idseparator:-
  :idprefix:
  :numbered:
  
  image::https://travis-ci.org/rillbert/giblish.svg?branch=master["Build Status", link="https://travis-ci.org/rillbert/giblish"]
  
  