Item stack duplication glitch

The Item Slot Duplication glitch allows the player to duplicate an item slot, allowing for over 255 of any item to be held. The most of an item that can be held with this glitch is 5100. It can also be used to change the "CANCEL" button to look like an item slot.

Requirements

1. 255 on an item in a slot below the first (A way to do this is to use the Old Man Trick and encounter a MissingNo..)
2. An unimportant item to the player in the slot directly below the item that the player has 255 of.

Procedure

1. Toss, use, sell, or deposit in the PC all of the item in the slot below the slot with 255 of an item.
2. The item slot with 255 will appear in the slot that was used for the lost item.

Notes

Items Acting as the Cancel Button

1. Using the glitch once will make the last item in the player's inventory act as the Cancel button. Using the glitch twice will make the second to last item in your inventory act as the Cancel button, and so on.
2. The player cannot scroll beyond the Cancel button, even though the scroll arrow is there.
3. Items below the acting Cancel button will be unreachable.
4. The acting Cancel button can be swapped with another item, which will act as the Cancel button.

Buying an item (or otherwise adding an item to the player's inventory) will erase the item acting as the Cancel button as well as those underneath it. A normally functioning Cancel button will be directly below the bought item.

Possible Dangers

One can lose Key Items from using this glitch.

Possible Uses

1. One can get rid of Key Items that they no longer need.
2. The glitch allows for faster duplication of items than encountering a MissingNo. by means of the Old Man Glitch