Paul sees use in delegating system IDs as long as they have a different keyword to public IDs. Norm is willing to try to figure out the ramifications. The word prefix is tricky, since what we mean is the starting substring, and prefix is used by namespaces. So we will go with publicIdStartString, though this decision may be revisited. Now we have two contentious issues left.
Norm proposes catalog.
It has the override attribute, which implements the override functionality of TR 9401. We need to define what happens if this isn't defined in the catalog. We could make override required. This is an issue. We may want to go beyond 9401, which makes it implementation-dependent.