Re: rel="shortlink" proposal for advertising short URLs in HTML/HTTP

[Barry Leiba <[e-mail]>]

Hm.

The problem, as I see it, with defining "persistence" is that one
wants different things in different contexts.  Consider these three
cases of things I might write:

1 ---------------------------------------------------
Note that any comments you post here are subject to my host's
copyright policy: [link to current copyright policy at time of
clicking].
------------------------------------------------------

2 ---------------------------------------------------
Note that the comment you just made is subject to my host's copyright
policy: [link to version of copyright policy in effect at the time of
writing].
------------------------------------------------------

3 ---------------------------------------------------
Check out the stupid typo in my host's copyright policy:
[link to immutable snapshot of copyright policy at the time of writing].
------------------------------------------------------

In case 1, I want a pointer that will always get me to the current
policy at the time you click the link.

In case 2, I want a pointer that will always get me to the policy
that's in effect when I wrote the text, regardless of subsequent
policy changes.

In case 3, I want a pointer that will always get me to the version
with the typo, even if they go and fix the typo without issuing a new
policy version.

With URL shorteners, you have no idea what you'll get, even when the
link isn't broken.  There's no guarantee that the content the link
points to has any relation whatever to what was there when the short
URL was made (if, say, the URL was set up to point to the current
front page of the newspaper).

With "short URLs" created by the content provider, you have a chance
of at least knowing what you're getting.  But what is it that you want
to get, and how do you specify it.  There are at least the three use
cases above, and perhaps others.

Barry