Re: [apps-discuss] HTTP header field for "URI lifetime"

[Graham Klyne <[e-mail]>]

On 20/05/2015 07:23, Erik Wilde wrote:
> hello.
>
> we had some discussions at www2015 about a possible HTTP header for exposing a
> URI's "lifetime". please do not get hung up on any terminology, but the
> scenarios we discussed included:
>
> - a service entering the sunset period and wanting to expose the fact that it is
> going to stop operating at some point in time.
>
> - a service doing archiving and wanting to expose that resources will only be
> kept until a certain time, and then disposed.
>
> - a service that might want to encourage users to check back regularly so that
> they might implement some strategy to check back periodically and see if the
> resource is still available or not.
>
> we could not think of an exiting HTTP header field for exposing this kind of
> information. i have two questions:
>
> - is there such a header field?
>
> - if not, is that something that people find interesting and possibly useful, or
> do people think that's not needed or even a bad idea?

Following the subsequent couple of messages, this seems like the goals might be 
somewhat experimental.  For such purposes, I think the desired effect *could* be 
achieved using a Link: header with a URI link relation; e.g., something like:

     Link: <http://example.org/RetentionInformation>;
           rel=http://linktype.example.org/retentionPolicy/

(If you don't want to store the retention information separately, maybe a data: 
URI?)

I see an advantage of such an approach is that you could experiment with 
different kinds of retention information by changing the link relation URI, and 
the approach might play nicely with a wider linked data infrastructure.

Just a thought.

#g
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