Please consider putting in an automatic feature or an option to allow automatic stacking of items in a player/item inventory. This should only be done when an item is first picked up and placed into the inventory or when an item or a number of like items are being transferred to another inventory (to-from chest/etc), not when a player is manipulating items already there (to allow for stack splitting). This should help alleviate inventory management for players, as well as to help optimize entity data and other background inventories on the map.