Er, test message

While lucid dreaming last night I ran into a DC (?) that insisted they were, in fact, another lucid dreamer. While I don't believe in the possibility of shared dreams (at the moment) they were quite insistent and so I told them this would be an effective way to settle the matter. I told them about this site and we had an agreed on sign-countersign.

The sign is "F".

(Has anyone attempted to put this to the test before in this fashion? Is there a better way to do it, too? I mean, if someone logs in and has the correct response I'll consider this a pretty compelling piece of evidence, but a third party wouldn't know if we collaborated in faking it.)