http://docs.mongodb.org/manual/reference/program/mongod/#cmdoption--sslAllowConnectionsWithoutCertificates

Changed in version 3.0.0: --sslAllowConnectionsWithoutCertificates became --sslAllowConnectionsWithoutCertificates. For compatibility, MongoDB processes continue to accept --sslAllowConnectionsWithoutCertificates, but all users should update their configuration files.

should say "--sslWeakCertificateValidation became --sslAllowConnectionsWithoutCertificates. For compatibility, MongoDB processes continue to accept --sslWeakCertificateValidation, but all users should update their configuration files."