Hippies Use Side Door Sign

Anybody know exactly what the sign read as referring to "blacks Use reverse side / back door" into segregation?

I seen the "Hippies Use Side Door" parody but can not seem to find a photo of the original racist sign that I need for a project.

behold some links http://bp1.blogger.com/_9QknraFPfQc/R88Xlk-yZwI/AAAAAAAAAXA/BjZHBfJiXvE/s1600-h/jcrowco.jpg http://pixdaus.com/pics/12076455956KmLuhD.jpg

Hippies use the side door

Hippies use Backdoor~ Metal Sign~ Approx 12 x 15 ...