DOCBOOK-APPS: webite bug?

2.0 website.

website-common uses variable $feedback.href.
Its not initialised anywhere.

I can't find anywhere where the config param
is used to set a variable.

In the autolayout.xml I see
 <config param="feedback.href" value="mailto:xxx"/>
This appears not to be transformed into a variable.

The result is that a feedback link is empty.

Regards DaveP