See the response at http://lists.w3.org/Archives/Public/xsl-editors/2005OctDec/0006.html.
We have taken the opposite approach and added the property values to the property defintions. We could now: a) just remove them or b) leave the values in and issue a warning when used Given that FOP 0.20.5 doesn't support this at all and it is therefore unlikely we would be breaking anything for users moving from FOP 0.20.5 to FOP trunk if we go for option a) I would recommend to apply the KISS principle in this case and just remove them. Manuel
