+\b \I{host key cache}Cache new host key type
+
+\lcont{
+Only available in SSH-2. This submenu appears only if the server has
+host keys of a type that PuTTY doesn't already have cached, and so
+won't use. Selecting a key here will allow PuTTY to use that key now
+and in future: PuTTY will do key here will cause a fresh key-exchange
+with the selected key, and immediately add that key to PuTTY's
+permanent cache (relying on the host key used at the start of the
+connection to cross-certify the new key). That key will be used for
+the rest of the current session; it may not actually be used for
+future sessions.
+
+Normally, PuTTY will carry on using a host key it already knows, even
+if the server offers key formats that PuTTY would otherwise prefer,
+to avoid host key prompts. As a result, if you've been using a server
+for some years, you may still be using an older key than a new user
+would use, due to server upgrades in the meantime. The SSH protocol
+unfortunately does not have organised facilities for host key migration
+and rollover, but this allows you to manually upgrade.
+}
+