I think I know what he means... The newer patches, people who are red/black and get pk'd have their items retained and if they don't pay cps to get them back, the player who killed them can claim them after a week or something like that... If they do pay the cps then it goes to the person who killed them.
It would be a fairly complex system to code (as far as npcs go). You would need a new database (or flatfile if it's lotf and you haven't converted to sql) to store what item belonged to who, cp value for it, when the item was retained, who pk'd them and such...
Then When the player is killed you need to do a random chance calculation to see what item(s) are retained, remove it from the client, add it to the database, calculate the cp value of the item (based on your servers economy) and finally print the required msg's to players who are online...
Then add an npc to pay the required cps to get them back (in which case the cp has to be added to the account who killed them, again, FAR easier if you are using sql instead of flatfile), they get their item back, the item is removed from the retained items database and the msgs are printed out to the server.
Finally do a check lets say every hour to see if any of the items in the database have gone unclaimed for x amount of days. If so, allow the person who killed them to claim the item(s) from an npc and obviously print the msgs's out to server and update the database when the item is claimed.
Also possibly add a 30 day check to see if it's gone unclaimed and if so delete it all together (if not if people quit your server your database will just get bigger and bigger needlessly)
Those are all the steps to it I can think of... some of them will be a bit tricky but it shouldn't be THAAATT hard.