The Recycling symbol has been more understood to us the more that we see it. It has a poetic approach because, at first glance, you don't really understand what it could mean. The series of overlapping arrows in a triangle symbolizes the reusal that recycling advocates. 

The red circle with the line striking through it is universally known as the No symbol. In every country, this symbol is used to show people what they are forbidden to do. It has a didactic approach because it is used and well known to stop people from doing what they're not supposed to be doing without directly saying "no."