You can be wearing at most one nontransformation mask and have at most one item on the item subscreen out. You can't equip over any mask you're wearing but can equip over any item on the item subscreen you have out. In human form, only items Link can have out are the sword, bow, deku stick, hookshot, and great fairy sword, empty bottles, and bottled items. Except for deku sticks with a counter at 0, using any item other than a bottle Link can have out will make Link have that item out. Excpet for magical mushrooms and the Deku Princess, capturing any item in a bottle will make you have that bottled item out. If you capture a magical mushroom or the Deku Princess, you will immediately put that item away and have no item out. Using an empty bottle will make you have the empty bottle out. Pressing the c-button for any bottled item will make no change to which item you have out or if you have any item out. Using any item on the item subscreen other than a bottle that Link can't have out makes no change to which item you have out or whether you have any item out. For any item link has out, an equip will make you put that item away if and only if no c-button has an item identical to that item after the equip. The game only keeps track of which bottled type of bottled item you have out, not which bottle you have out. For example, if you capture a fish and the other c-buttons don't have a bottled fish on it, you will not put the bottled fish away if you equip another bottled fish over it but will put it away if you equip a bottled fairy over it. Since there's only one of each item other than a bottle, equipping over any item other than a bottle that you have out will make you put that item away. You can only do the bottle method of the Stop Time glitch or ESS bottle duplication with a bottled item you have out.