It's a good thing the Order never did it properly. Imagine if they actually followed their *procedure* for a change:

Remus:(approaches with a massive grin)
Harry: Hold it right there! How do I know you are
Remus?
Remus: Oh? Well how do I know you're Harry?
Harry: Prove that you're Remus!
Remus: You prove you're Harry first!
"No you first!" "Not before you." "No way!" "You sanctimonious little son of a Squib..."