Custom tags in Docbook

[Oscar Pereira <oscar.pereira@anubisnetworks.com>]

Hi,

I am a novice user of Docbook, who has just subscribed this list hoping 
to see answered a question that a lot of googling could not. I was just 
tasked with completing a docbook document (using xml) that someone else 
had already drafted. As I analysed that document, I found that word 
emphasis were being done with <emphasis> tags, throughout the document. 
I found this odd because, some of the words represent classes of data, 
that should have a coherent formatting. I have some experience using 
LaTeX, and one of the first things you learn is how to define commands 
for specific things (which is rather simple to achieve). Making the 
transition from commands to tags, I was hoping there would some equally 
simpler way of defining tags that could be applied to custom classes of 
data. This way, instead of writing <emphasis>search</emphasis>, I would 
like to write something like <guibutton>search</guibutton>. This way, if 
at a later time it was found that gui buttons should be written in bold, 
changing it would be simple: which is not the case is you use <emphasis> 
all document long (and for other things that are "gui buttons" in my 
example). Googling for a way to do this yielded a lot of things about 
dtds and xsl, but nothing that answered my question. Is there a way to 
do this? Or I making some error regarding the way DocBook should be used 
(perhaps from my previous background working with LaTeX)?

Please note that I have a somewhat limited knowledge of XML and XSL, and 
so I was really looking for a simple solution...

Thanks in advance (and apologies for the long mail),
Oscar