Sometimes you want to an item in your EA model to point to another one, from the text of the description field. This is is a more informal style of link than creating a relationship between the items, but iy's useful when you want the text to say e.g. "See Use Case 42 for more details" or " remember that Component1 is also useful'.

You can create these links using the 'link' in the EA 'notes' editor:  

Now when you create a document, eaDocX will automatically create a hyperlink to the referenced item, provided the item is elsehere in the in the document. 
This could be to any of a Package, Element, Diagram, Operation or Attribute.
Clicking on the link will take you to the referenced element in your EA model. This is a great way to allow readers of your model to navigate from one part of your model to another. It's especially useful within Package notes, to point the reader to particular contents of the package, or to other related packages.
For more information, see the eaDocX Help