In a nutshell, taking blood fractions has become a conscience issue. In the past, this was unheard of. Anything in any way associated with blood was a no-no. The 4 major elements of blood (red blood cell, white blood cell, platelets, plasma) are still not allowed. (The WT, not the medical field has defined what these 'major' elements are)
Why is it presented in such a complicated way? it's to hide the fact that basically blood transfusions have now really become a matter of conscience. Why do they want to hide this under a veil of confusion?
Can you imagine what would happen if they flat out came out and announced that taking blood is now your personal decision? Current and former JW who have lost loved ones in the past would sue them for every penny and the public outcry would be enormous.
So to minimize the damage, they have introduced a new DPA which replaces the old blood card. Now YOU have to choose which fractions your conscience allows you to take on the DPA. That way if anything happens where you lose your life because of blood complications, the WT is not liable. Are you kidding me? Last I checked, most of JW are not experts in the medical field. How are we supposed to know which fractions should be considered 'holy and unacceptable'? I have to reason that 99% of JW who fill out that form will accept all blood fractions that wont get themselve DFed when their loved ones lives are on the line.
As for the 4 'major' components that are not allowed? That's a joke.
Ex: If I need plasma (which is 97% water) to live, would you consider that blood?
White blood cells are transferred from mother to child when breast feeding. Is the baby drinking mom's blood?
The doctors can always find a way around these idiotic technicalities if there ever is an issue. So basically, blood transfusions have become a personal decision and if you die because you refuse any blood component, it is your responsibility. If you filled out the DPA, you cant sue the WT society.
You'll never read that in the WT though. Instead you get the encrypted version.