Turning off generation of epub cover

Is there an easy 
way to turn off the generation of a front cover? I have set up a DB 1.76 NS 
customisation that always generates a "cover.html". I've tried various 
options in the epub titlepage (where I have a template 
name="book.titlepage.recto" similar to the FO titlepage template) by adding 
a param value that lets a user select the cover on or off, but I'm lost. 

 

What I'd like is to write in an option that allows: no 
"cover.html" to be generated; and exclude the associated cover image info 
from toc.ncx and content.opf. I can't follow the logic of covers in 
docbook.xsl. Any ideas please?

Thanks 

Dave Gardiner