With the proposed changes to blood regeneration and blood bags, THERE ABSOLUTELY MUST BE some way to mark the bags with a blood type. Either manually with a pen, or have it done on it's own when the bag is filled.
As of now each person must carry their own blood bag in order to not die on accident. It makes a person who acts as a medic have to either have a super good memory, or keep blood bags of different types separated. Which is mega impractical.
Please do not overlook this.