Another thread has caused me to ask this question.
P411 & Date Check use your ID number and your initials as your identifier. When asked, you are to present those to a provider so she can verify that you are indeed that member.
I've met with a few that have used that check. One well known provider states in her website that she will ask
Dawgs - Does it bother you to show your ID to a provider? If so why?
Ladies - do you ask, at least maybe sometimes?
It doesn't bother me, as long as the ID stays in sight.