If "Visitor center" is acceptable, in singular but not genitive, why, then, would "Visitors center" not be equally acceptable, as plural but not genitive. When something is FOR someone, rather than being their possession, it all got murky when I tried to insist, to myself or anyone else, on a "correct" version.. But I got over it However, I'm sure sticklers and style guides will have something definitive to say..., En plena oscura traducción, me ha asaltado una duda con nocturnidad y alevosía! En castellano se escribe "Párking" o "Párquing"? O ambas formas están aceptadas? Gracias mil, chicos! EM, You could say "parking is not permitted here," "you may not park here," "you are not permitted to park here," "parking is not allowed here," or several other turns of phrase. While your sentence is not grammatically incorrect, it is not considered good colloquial (or formal) English. "Allow" is fine..