anchor.diff:  
       {
   		    "version" : "...",
  +		    "snapshot" : "...",
   		    "event" : "...",
   		    "data" : "...",
   		    "tag" : "..."
  
positive.code: By default, new version must be backward compatible which means that a consumer should be able to deal with an event flagged with an older version.
  
  Version format follows the http://semver.org[semver] protocol.
  
  === event 
  
  
negative.code: The `ADD_CATEGORY_ITEM`, `READ_CATEGORY_CATEGORY` and `UPDATE_CATEGORY_ITEM` events for an `Organization` have a `data` attribute associated to a value that looks like this:
  
      {
          "category": "The category ID"
          "name" : "The name of the item"
          "picture" : "The picture of the item"
      }
  