We require the following, minimum content supported in vCards for contacts:

• email
• firstName
• lastName
• role
• phone
• birthday date
• timezone
• street address
• country address
• city address
• postal code address
• region (maybe not mandatory)

As for the firstName/lastName I am not sure how related to this is currently supported structuredName and formattedName. Maybe this would be enough and we do not need first/last names. I am not sure at this point.

Taken from GitHub