I found out that my blog software (blitiri__) already support tag-specific
feeds, you just have to some extra GET variable(s) to the URL, for example::
- http://www.llucax.com.ar/blog/blog.cgi/atom?tag=en&tag=self
+ /blog/blog/atom?tag=en&tag=self
__ http://blitiri.com.ar/git/?p=blitiri