What a timely discussion. In the morning, Montana State Library will be 
attempting to answer the question: do we need to continue making 
permanent URLs to access our state pubs collection?  It's not clear to 
me what the handiness of permanent URLs is. Just tried a PURL from 
our Montana state pubs collection. What appears in the address bar for 
bookmarking when the resource is access is NOT the PURL id but the 
target URL at the Internet Archive?

According to a recent post here on a similar topic, John Kunze, the 
creative developer of ARKs, said for permanency to take place, one 
needs a reserve access repository in place. 

So, we set up and maintain PURLS at purl.org for a long-term horizon 
say 50 years. We setup a reserve repository. We create a bridge table 
for redirecting our targets from IA to the reserve repository when we 
need it. If we need the reserve targets, we modify the PURLS at 
purl.org. It takes two days, which is OK for legacy state publication 
because the current ones are still online. 

Are we are good to go for fifty years from now when a move is needed? 
In the meantime, the reserve repository fails, or purl.org fails, or 
nothing fails, but URL technology changes or repository technology 
changes. What we actually need 50 years from now is nothing like we 
have set up to help us make the transition to reserve repository. So, 
maintenance of permanency is more than creating permanent URLs, it 
means keeping up with 50 years of obsolescence. 

Why not tend to the links in our catalog. Plan in a detailed way to shift 
to a reserve repository understanding the target links required. Change 
this plan every time obsolescence rears its ugly head. When the plan is 
needed, do it. If there are still URLs, generate the new target list and 
the bridge table from current records if there is still such a thing. 
Overlay the records and be good to go with whatever actually is needed 
at the time its need? Say it take 30 days to do this. This would probably 
be OK for state publications. In the meantime, save time and money 
creating and maintaining permanent URLs that will be obsolete when we 
need them.

What am I missing?