advice alert announcement appropriate-behavior appropriate-behaviour avoid be-careful beware black care caution communicating communication concern crocodiles crocs danger dangerous directions information informing no-swimming not-allowed not-permitted permission-denied prohibited prohibition protect protection red risk risks risky rules safety sign signs swimming unsafe warning 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 area attention banned cigarettes direction directive distinctive environment eye-catching glassy health health-risk location no-smoking plastic pollution raised style surface surfaces surfacing symbol tactile texture textured textures thick thin unhealthy wording words lettering semi-transparent surfaced