cloud clouds flag half staff lower lowered mourn Poland pole polish sky staff insiders limited access no public access prohibition restriction sign staff only warning workers 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 access-denied alert authorised-approval authorized-approval behave behavior behaviour communicate denied direction entry-denied entry-prohibited exception keep-out limitations no-access no-entry not-allowed not-permitted permission-denied prohibited staff-approval staff-approved unauthorised unauthorized 3-D conditional conditions eye-catching glassy informative limited-access liquidy no-public-access notification notifying plastic raised security semi-transparent words clear transparent ban danger trespassers zoo note notes paper sheet music