RE: now://example.org/car (was lack of consensus on httpRange-14)

Roy, I build police databases for a living.  VINs 
are known items here.

A VIN is used to access a record for entities that 
have an involvement with that car.  It is a standard 
relational operation.   It acts as a lookup key, 
nothing more.  As an identifier, it is assigned by 
the manufacturer who maintains the list.  It is a 
morphological URN.  It can be used for retrieval of 
documents.  Identifying the car is a little more 
difficult because VINs are hidden all over 
the car's parts to ensure it is difficult to impossible 
to erase.  Persistence over chop shops, yes, but 
when parts are reused, the VIN becomes a confusing 
item.  It can tell you what car the part was originally 
on, but can't identify the car it is on now.

URIs are URLs in the web system.   Because they are syntactically 
the same, one can pass them to the resolver and it will attempt 
a resolution.  There is no surface way to distinguish these and 
as a result of that, if a URL is used as a name, one gets a 404 
or whatever back because not only the human, but the software 
can't tell how to use the overloaded symbol.

I agree one should stick a fork in this.  However, the notion 
that for all names one should use http: strings won't hold should 
anyone decide that they must have a non-dereferenceable string.  
An http: symbol in the current implementations are ALWAYS 
dereferenceable.  There simply may not be any representation 
to return.

len


From: Roy T. Fielding [mailto:fielding@apache.org]

Consider the VIN to be a reasonable identifier for a car.  Is the fact that a VIN
identifies a car in any way restrictive of the ways that people exchange
or use VIN numbers?  No.  When you use a VIN number for the purpose of
arranging financing and registration, the car is not accessed in any way.
Likewise, when a car is parted-out and found by the police, they use the
VIN to perform a registration look-up on the owner.  The identifier just
identifies the car, but it can be used to identify the owner, the leasing
agreement, the manufacturer, the creation date, and even a police record.

>All locators are also identifiers.  Whether something is a name or a
>locator only impacts its ability to be directly used to locate the
>resource, not its ability to identify the resource.

Received on Friday, 11 October 2002 09:55:50 UTC