OID value: 1.3.6.1.4.1.311.20.2.2
OID description:
Required to be present in certificates for Microsoft Smart Card Logon for Windows.
URL for further info: http://support.microsoft.com/default.aspx?scid=kb;en-us;287547
See also the OID Repository website reference for 1.3.6.1.4.1.311.20.2.2