OID value: 1.3.6.1.4.1.1466.115.121.1.50
OID description:
Values in this syntax are encoded as if they were Printable String
types. Telephone numbers are recommended in X.520 to be in
international form, as described in E.123 [15].
( 1.3.6.1.4.1.1466.115.121.1.50 DESC 'Telephone Number' )
URL for further info: http://src.doc.ic.ac.uk/computing/internet/rfc/rfc2252.txt
See also the OID Repository website reference for 1.3.6.1.4.1.1466.115.121.1.50