Formatting XML Data

Hello, I have been working with XML in the recent weeks and I have recently come across the need to format some of the data in my XML. For example I might have a large XML file and I would like some of the text to be bold, or maybe I would like to insert a hyper-link. Unfortunately it does not seem I can do this with ordinary HTML tags because they will be interpreted as XML tags. I am sure, however that there is another way of doing this. Does anyone know how? Thanks