A conventional symbol is a symbol that has an understood or widely accepted interpretation. The heart, for example, is a conventional symbol of love. There are other conventional symbols that are easily recognizable. For example, we pledge allegiance to the flag, which is a physical, tangible representation of our country. Even as children we know that the flag isn't the country, but that it stands for our country. The pledge is a statement of loyalty to the country, and not a statement of loyalty to a piece of decorated fabric.