Backpacks, Belts and Pouches are good described in the
wiki
I would like to share my thoughts on this topic with some ideas that may enhance or deteriorate the system.
On backpacks beside what the wiki says that there will be different types of backpacks eter to gather or to transport i would like to add here:
that access to its inventory may be shown in UI however to interact with its content the player needs to be in non combat mode. so during combat he can not use items from the backback.
to the belt i would then add that the items on the belt are especially for use during combat and may bring a separate ui quick access to its content.
On the stack size the belt holds potions/scrolls that may stak to 100 however if a backpack is equipped the belt can pull the potions/scrolls direct from the Backpack//Pouch and so grant more than only 100 potions/scrolls like it would without a backpack/pouch.
in addition to what the wiki has described here some pouches:
pouches can be equipped to the belt and depending on their crafting level and rarity can hold more items in total and bring more slots.
The scrolls on the belt itself can be directly used in combat. In off combat all scrolls can be used from the Scrollpouch. depending on the rarity of the pouch it does have instant use slots. all scrolls on these instant slots could be linked to the UI and also used during combat.
A money pouch is also attached to the belt it is physically there and to be carried the more money the heavier it gets with the rarity the weight of its content is reduced to to point on negated on the highest rarity. May also have a maximum of money it can hold depending on the rarity.
poches could be enchanted to grant some effects like the insand use slots or the weight reduction. also may protect partly from getting lootet depending on rarity or enchantments.
In addition to the Backpack mabe a Fanny pack could be used that holds less usebels than a backpack but also weighs less.
especially if weight does affect the movement speed of a char.