ISPs, proxy servers, and your local machine all do caching. If
a system ID doesn't change much, then setting reasonable expira-
tion times on it will help. There is no need to work in another
resolution mechanism, in my opinion.
We need to try to make XML simpler, not more complex. Just be-
cause PubIDs (barely) made it into the standard doesn't mean we
must immediately begin pushing the envelope of what they can do.
They're there primarily for legacy SGML compatibility.
Work would be better spent on URNs.
Richard Goerwitz