[...]
>An FPI is persistent because ISO legally constracts to not reassign them.
>This may mean nothing technically, but neither does the fact that the
>American government legally asserts that e-commerce transactions based on
>USD have value. If either ISO or the American government goes out of
>business, their promises are worthless, but by then we'll have other,
>bigger problems than our links breaking (which, I guess, is the real
>point).
I think we need to be careful what thing we're talking about when we use
the term "persistent": the name or the resource.
A name is persistent if it is never re-used, that is, if once assigned, it
always gets you to the "same" thing and, if that thing ceases to exist,
gets you to nothing. A thing is persistent if it exists for as long as we
care about its existence.
SGML Formal public identifiers are not necessarily persistent names because
there is nothing in ISO 8879 or ISO 9070 that requires them to be (nor
could such a requirement be enforced or validated). All that ISO 9070
provides is a process for registering *owner identifiers*, which are,
presumably, persistent (at least as defined by the assigning body).
However, the name owner is responsible for managing the names within their
slice of the FPI name space and can do whatever they want with them,
including reassigning them without regard for persistence at all.
Cheers,
E.
-- <Address HyTime=bibloc> W. Eliot Kimber, Senior Consulting SGML Engineer ISOGEN International Corp. 2200 N. Lamar St., Suite 230, Dallas, TX 75202. 214.953.0004 www.isogen.com </Address>