> I would be content if [FPIs] could be viewed as
> one long silly-looking string that we use in a character for character
The original request (and the 5,00 lines,0 I think) included Formal
Having said that, if you don't care what's inside the FPI, it might as
well be any string. So it could be a string that looks like a URL.
So it could be a URL. In particular, it could be the same string as
the URL used for the system identifier for the DTD.
In other words, another way to look at it is that XML _only_ has public
identifiers, but all XML public identifiers are actually called SYSTEM
rather than PUBLIC, and take the form of URLs.
The only thing in practice today that an FPI gives you is that you can
compare it to one in a printed standard... anything downloaded over the
net is likely to differ from the formally published text anyway, and there
is not yet any way to resolve FPIs automatically that does not involve
writing a letter to the GCA or ISO...
If you want the kind of indirection a catalog gives you, you can use
Apache 1.1 and put Redirect or Alias commands in an .htaccess file.
For non-Internet use, I don't see FPIs as an issue right now.