vCard is a file format for exchanging electronic business cards. Usually they are used to send information like phone numbers, postal or email addresses. The version 2.1 of the format was specified by Versit consortium in 1996, followed by an IETF specification for vCard 3.0 in 1998. vCard Test Suite can be used for testing both vCard 2.1 and 3.0 implementations for security flaws and robustness problems.
vCard - The Electronic Business Card Version 2.1
A MIME Content-Type for Directory Information
vCard MIME Directory Profile