The Bag of Holding plugin (https://lone.design/product/bag-of-holding-rust-plugin/) spawns special bags that start off with the ability to store specific categories of items in each bag. For example, you may find an XXSmall Weapons and Ammo bag. In this bag you could only put, naturally, weapons and ammo. Bag of Holding can be upgraded using scrap. If you upgrade a bag enough, you can put anything in the bag. You are no longer restricted to the category of the bag. Bags of Holding spawn randomly in loot containers.