This is a question I have come across many times with my customers, and I can 
not find a documented answer,
 
The customer has 100 client licenses and 100 clients, the customer decides to 
decommission 1 of those clients, and wants to reuse the client license.  If the 
customer deletes all references to that client from the configuration, but puts 
an infinite retention time on the last full backup of the client.  Will the 
catalog entries for that last backup be deleted, or will they remain in the DB 
for recovery to an alternate client.