Stamp1.png
Inventory shows items you have marked
Stamp2.png
You will see this menu when you ctrl+rightclick any item in inventory.
Stamp4.png
You can change the Stamp even with a note added in item
Stamp3.png
Adding a note for item
Stamp_v4_1.png
Stamp v4 dropdown contains new texts: OPEN, USE, D/E and AH