clean clean up compulsory green litter man mandatory Mandatory sign no litter no trash no waste roadsign roadsigns sign signs trash trash can UP waste box dump dumping flying garbage graphic icon no notebook notes paper papers rubbish sheets stationery warning creating time making time no time terrestrial time. time wasted time- honoured time-in time-out too much time directions forbidden forest rules home path pictogram road appropriate-behavior appropriate-behaviour clean-up cleanliness communicating communication dog doggy-do droppings excrement excreta hygiene informing mess messy not-allowed not-permitted pets pickup poo prepared prohibited prohibition responsible rules sanitation