I just heard about this non-discrimination sign requirement today but it has pretty broad application.  It is not a federal requirement but it has to be prominently posted in every NJ place of public accommodation as defined by New Jersey Law.

"The regulations of the New Jersey Division on Civil Rights require that all places of public accommodation who are covered by the New Jersey Law Against Discrimination shall display this official poster in places easily visible to all persons seeking or using the accommodations. N.J.A.C 13:8-1.4."