[UFO Chicago] xkcd.com question

[Greg Neumarke]

On 2/8/2012 2:04 PM, Jay F Shachter wrote:
> I really need to be working on something else today, but I gotta ask
> this:
>
> Can anyone explain the text in small print at the bottom of xkcd.com,
> right above the words "This work is licensed under a Creative Commons
> Attribution-NonCommercial 2.5 License"?  I have to know.  Thank you
> in advance.
A quick Google turns up this:
http://blog.xkcd.com/2007/04/19/billboards/

-Greg