Thanks Michael for the detailed explanation. Never used "mode"
attribute but seems to perfect in my case.

One more question, don't you think that <xsl:import> or <xsl:include>
(although I still do not know much about these two elements) will be
more helpful in this case to avoid the long and complex stylesheet. I
would prefer to modularize this rather having a single stylesheet,
which later will be painful, if debugging is required.

Personally, I don't think that splitting code up into different
stylesheets is a guarantee for less pain. But then, I'm not a very
experienced XSL user.

But of course it may look more orderly to you. And if that is the
purpose, why not go ahead and use xsl:include? To give an example, you
might organise your different modes in stylesheets by the same name.

An xsl:import is used to override definitions in the calling stylesheet.
An xsl:include is just a simple inclusion. Which one is better for you,
depends on your approach. If unsure, pick xsl:include, which is simpler
in concept.