I just received a new donor card from Canadian Blood Services.It has my blood type on it but I don't know why?
Given the danger of mismatch, would anybody ever be willing to take this assertion on face value and not directly verify my blood type? If I told the nurse my type when I went in to donate she'd smile at me and say "That's nice dear, but let's check anyways shall we?". The claim as to type on the card might as well be similarly self-asserted.
So, what purpose does the blood type assertion on the card serve?
Maybe it's some sort of confirmation method for the token. If my tested type matches that on the card then that's some evidence that I am indeed the valid owner of that card (further evidence probably provided by separate identification).
Apparently, only 6% of the Canadian population has my blood type. It's like I'm like an online banking site with exclusive criteria for which IDPs I'm willing to accept assertions from. In this case I think I'd prefer to be more like some "universal recipient" blog site.
Update: Anon's comment makes sense. The blood type is there for me, and not for the 'relying party'. Is there an electronic analogy? Perhaps a friendly name on a long-lived token stored on a smart device in order to remind the user of its applicability?
Update 2: Pam trumps my 6% with her 2%. Big deal, it's not like I had any sort of emotional investment in my relative uniqueness .... I do think I'll demand a recount though. Maybe the chads were hanging.