Private card details are the parts of a contact card most people shouldn't see: date of birth, home address, passport details, pay rates, emergency contacts, and medical and food notes.
WHO ALWAYS SEES THEM: the tour manager, the production manager, admins, the tour accountant, and the person themselves (their own card).
WHO ELSE: the tour manager picks, on the Tour Roster page, Private card details. Tap a role to turn it on or off: Business manager (on unless the TM turns it off), Management, Artist, Band, Crew, Driver. It saves right away and applies to everyone with that role on this tour. Everyone else still sees the roster: names, roles and phone numbers (unless the TM hid a person's contact info).
NEVER SHARED: bank details and Social Security numbers are never on a card. They stay in each person's own Me page.
WHO CAN CHANGE IT: the tour manager or an admin. Anyone else who opens it is told to ask the TM.