the pixels in the sky textures

I've been looking for information concerning the pixels that run across the top of the sky textures.I seem to remember one of the ACES members (or maybe somebody else) giving a description of what each pixel did. I cant seem to find that info. pixelpoke seems to have come the closest but I couldnt find it on his blog either. that doesnt mean I didnt search incorrectly though.If you know where that info is or you know what those pixels do then I would appreciate your help.thanks in advance.