insiders limited access no public access prohibition restriction sign staff staff only warning workers ban danger trespassers zoo acceptable advice advising allocated allocation appropriate-behavior appropriate-behaviour approved black blue carpark communicating communication directing directive indication indicator information informing limited limited-parking parking restricted restrictions signs special-parking staff-only staff-parking white word 3-D conditional conditions eye-catching glassy informative limited-access liquidy no-public-access notification notifying plastic raised security semi-transparent words clear transparent artistic artwork color coloration colored colour coloured contrast copper-art copper-work copperwork coppery craftsmanship decorative designed distinctive embossed embossing expressing expression impressed lettering patterned patterns perspectives presentation