Re: Persistent Documents and Locations

William Y. Arms (warms@CNRI.Reston.VA.US)
Tue, 22 Aug 1995 13:40:26 -0500

Message-Id: <ac5fccb901021004e002@[]>
Date: Tue, 22 Aug 1995 13:40:26 -0500
From: "William Y. Arms" <warms@CNRI.Reston.VA.US>
Subject: Re: Persistent Documents and Locations

At 6:21 PM 8/21/95, Karen R. Sollins wrote:

>The intention for
>URNs is that they are valid in perpetuity.  If the object is still
>around, in 10 yrs, then the URN for it is still "valid".  I can't go
>into a long diatribe now, but there is a great deal behind the choice
>of making URNs global and long-lived.  But, suffice it to say that
>URNs don't expire or become invalid.   The resources they name may be
>deleted, but the URN should never be re-used or reassigned.  For each
>URN the assigment of it happens no more than once, ever.

I agree completely with Karen's point of view.  A name is a name is a name.

In practice, the names refer to objects or resources which are parts of
application systems.  Those systems will usually wish to impose various
controls on the resources and their names.  Possible controls include:
    each resource has only one name
    each name refers  to a unique resource
    changing one bit of the resource requires a new name
    dangling names are not allowed
and so forth.

Such controls are extremely important in practical applications.  However,
a "pure" naming scheme simply links names to resources and lets
applications systems specify controls.