It used to be that blue ink would not copy on a copier, so the rule was that all handwritten medical records must be written in and signed in black ink.
Now some attorneys are counseling people to sign documents in blue ink, as it stands out from the black text and can be verified as “original.”
My mentor taught me to always carry a red pen with me, so when you sign an attendance list or guest log, your name will jump off the page!