Stackable items are items which only take up one space in a player's inventory. When multiple stackable items are carried in the inventory, a number is shown on the item's picture to indicate the quantity of items in the stack. Stackable items do not weigh anything, and cannot be withdrawn as a bank note. Stackable items include coins, runes, arrows, seeds, bank notes, purple sweets and other items such as feathers, arrow shafts, nails, bolt tips, skewer sticks, woad leaves, and proboscises. Also, swamp tar and anything made from swamp tar, such as swamp paste or guam tar, is always stackable. Most items appear to be stackable in a player's bank to preserve bank space.
Limit of a stack
The maximum quantity of an item a player can hold in a stack is 2,147,483,647 (2³¹-1). This is because the value of a stack is represented as a signed (positive or negative) 32-bit integer. This could be improved by making the coin value an unsigned (only positive) 32-bit integer.
When referring to numbers, truncation is the removal of insignificant digits from the end of a number.
In RuneScape, stacks of items have their quantity truncated to reduce the number of characters required to show the quantity of an item in a stack.
For stacks of items containing less than 100,000, the amount is rendered precisely, such as "31337", and the examine text is that of an individual item. For stacks 100,000 or more, the examine text displays the exact number of items in a stack, and the following conventions are used to display the quantity in a bank or inventory slot:
|0||99,999||Yellow||None||1||99,999 displayed as "99999"|
|100,000||9,999,999||White||K||1,000||9,999,999 displayed as "9999K"|
|10,000,000||2,147,483,647||Green||M||1,000,000||999,999,999 displayed as "999M"|