Other vendors may add fixed up handlers in the same way to support
their existing products.

But that is exactly what we don't want. Why bother adding a generic
protocol, if vendors then hack it around to make it compatible with
whatever their legacy systems have? We want to discourage such bad
behaviour.

How do we discourage this? We add the label 'legacy' everywhere we
can, so it looks bad. We put the legacy code into a module, behind a
symbol with LEGACY in its name, which is disabled by default.

The messaging i've seen from ST is that they will use the generic
protocol. We reward them for doing this by not bloating the code they
need with legacy support for other vendors...

     Andrew