+You should normally leave this at the default, \q{2 only}. The older
+SSH-1 protocol is no longer developed, has many known cryptographic
+weaknesses, and is generally not considered to be secure. If you
+permit use of SSH-1 by selecting \q{2} instead of \q{2 only}, an
+active attacker can force downgrade to SSH-1 even if the server
+you're connecting to supports SSH-2.
+
+PuTTY's protocol 1 implementation is provided mainly for
+compatibility, and is no longer being enhanced.
+