Item Type issue

[KeiKun]

IT_CASH that IT_USABLE doesn't have

• Cannot stack particular item after using @item or cash_shop, you have to use
  mergeitem()
  to allow the item to be stack on your inventory
  
• Prompts confirmation window if you want to open use it
  
• Has Unique ID
  

Like is there a way, i can make a custom type which

• can stack directly upon using @item or cash_shop
  
• prompts for confirmation