alert appropriate-behavior appropriate-behaviour area attention banned boundaries boundary cigarettes communicating communication danger direction directive distinctive entrance environment health health-risk limits location no-smoking not-allowed not-permitted penalties penalty permission-denied pollution prohibited prohibition shopping-center shopping-centre sign symbol thick thin unhealthy warning wording words advice announcement avoid be-careful beware black care caution concern crocodiles crocs dangerous directions information informing no-swimming protect protection red risk risks risky rules safety signs swimming unsafe warning-sign water white aware awareness careful colors colours considerate consideration Dirt dirty garbage green limitations limited listen lookout rubbish unwanted waste waste-disposal watch-out 3-D eye-catching glassy plastic raised style surface surfaces surfacing tactile texture textured textures lettering semi-transparent surfaced