Found on GameSpot forums.
My results with the code: key items still appear to be present, but are now overwritten with other items, unlike in previous attempts. It also cleared my Ball pocket. It should work for Action Replay (North America) and AR Duo, possibly others as well.
RNG Kill - [Patch type]
66BC3257 9381D042
8E883EFF 92E9660D
Button Activator - Press Select+L
3CDE8216 3875A404
Clear Key Items Pocket (RNG)
A589B85A 5B28BA0A
C9E803DF 568E296C
After activating all 3 codes at the same time:
1. Open the trainer card
2. Press B
3. Press Select + L
4. Check for results. If they don't show, don't worry about it. Just save and test by switching bikes or obtaining a key item.
you can't
select
you can't delet key items in any Pokemon games.
where you use the key to turn on the quary.
You can't. You can re-arrange them so that the ones you want are at the top using select, though.
it is impossible to do that unless you start the game over again and don't collect the item you don't want
As far as I know there is no code for key items.
Ruby & Sapphire Key
You can unregister them but you can't remove them from your pack
Key items are impossible to trade or remove, except to Pokémon Colosseum.
Unduplicatable ItemsThe only Items you can't duplicate in Emerald are Mails, because you can't store a Pokemon holding Mail into a PC. You can't clone any Key Items either.
you can't
When facing water, open your bag and go to key items. There select the Super Rod and then use it.
There is no key it opens when you become a Pokemon champion.
select
you can't delet key items in any Pokemon games.
Watson gives it to you