DITAbase for conversion

I understand the compatibility problems between constrained and
unconstrained conrefs. It shouldn't present a problem in environments where
DITA 1.1 DTDs are upgraded to DITA 1.2 DTDs with the unconstrained task
model. It is not a backward compatibility issue. Technically, the older DITA
1.1 task topics will also be unconstrained but be written to resemble the
constrained task model.

Cheers,
Rob