-PAPER STACKING-
I have noticed paper is not stackable ingame,
I find this odd when paper is stackable in real life and many other ingame items are stackable such as bullets, burlap, rags, even large items such as planks are stackable.

-LETTER WRITING-
As far as I understand the ability to read/inspect paper is currently in game but not the ability to write a message on the paper.
My suggestion is for the player to have the ability to write a message on the paper changing the item name from "paper" to "letter"
This would allow players to leave the "letter" for other players / team mates to pick up and read. This could be useful in many different scenarios.
An extension of this idea would be to combine the "letter" with a knife to give the player the ability to "pin letter" to vertical objects with the knife objects such as doors, fences, gates buildings/ walls and trees making the "letter" more obvious and slightly threatening.