anchor.diff:  "[\"^ \",\"~:type\",\"~:query\",\"~:dest\",\"~:users\",\"~:data\",[\"^ \",\"~:some\",\"^4\"]]"
   ----
   
  -*postal* comes with a set of predefined messages with specified semantics but that
  -not limits the user to define own messages on top of that protocol.
  +*postal* comes with a set of predefined types of messages with specified semantics but that
  +doesn't limit the user to define their own messages on top of the protocol.
   
   
   == Common Messages
  
positive.code:  :data {:foo "bar"}}
  ----
  
  After sending a `:publish` message we should expect an `:response` message to be
  sent back or `:error` if an error is ocurred. The `:dest` property is mandatory.
  
  
  == Clients & Servers
  
negative.code: 
  === :subscribe
  
  This is a message that should be used for notifying the server that a client wants
  to subscribe to a specific topic.
  
  [source, clojure]
  ----
  