Graffiti is the expression of visual idea as seen or conceived by an individual, and has been developed from its original form through three distinct phases, the imitative, transition and apocryphal phases. The imitative phase shows drawings imitating the surroundings of the graffitist. The transition phase uses words to express social ideas, personal thoughts and messages. The apocryphal phase consists of words made to look like drawings or characters, which can be understood only by a professional graffitist. Apocryphal graffiti, known as tagging, is of two types, individual tagging and group tagging.