There are specific items in our inventory that has a limit on how many we can have. One good example that we normally request from friends or collect from feeds is the Baby Bottle. As we notice inside our inventory, we can only have up to 12 pieces of Baby Bottles regardless of how many bottles we accepted from requests we sent out and collected from wall posts. When we reach the limit of 12, all other bottles that we accept won't be added to our Inventory. The best way to maximize all of the Baby Bottles that we requested or collected, is to make sure we use our current bottles inside the inventory and then collect other pending bottles one at a time.
This example goes to all items in our inventory that has their specific number of limits.