Dropping destroy-only items and pets glitch
With the RuneTek 5 update on 2 September 2009 that allowed players to drop items with their bank open, came a glitch that allowed you to drop 'destroy-only' items on the floor (such as holiday items or achievement diary rewards). This could also be done with pets, but the pet would be in item form, not an actual pet. This could also be done with Barrows armour, allowing it to be dropped without it getting broken.
These glitches were both fixed with a live update a few hours after their discovery.
This glitch can also be done when dying. When a player dies while having a 'destroy only'-item and returns to their grave marker to pick up their lost items, the 'destroy-only' items will be dropped there too.