clarify that not understanding a verification method should not auto-cancel
@@ -28,7 +28,10 @@ appropriate `m.key.verification.cancel` message is received. If Bob chooses to
reject the key verification request, Bob's client should send a
`m.key.verification.cancel` message to Alice's device. If Bob's client does
not understand any of the methods offered, it should display a message to Bob
-saying so.
+saying so. However, it should not send a `m.key.verification.cancel` message
+to Alice's device unless Bob chooses to reject the verification request, as Bob
+may have another device that is capable of verifying using one of the given
+methods.
To initiate a key verification process, Bob's device sends a `to_device` event
to one of Alice's devices with the `type` set to `m.key.verification.start`.
