Design needs to make use of codes in order to form communication, whether it follows traditional codes or breaks them it is still making an association with certain values, attitudes, beliefs, assumptions and practices held by the reader. A lot of these values are not controlled by the reader, but rather by social and cultural beliefs.

A lot of the theory on catagorising codes within visual communication is still very divided, with most theorists holding a different point of view on what codes and sub-codes should be grouped.

The dominant groups of codes found in design, as I see them, are medium, type, space, colour, time, image and sound. These codes can be further broken down in to many sub-codes. I have briefly explained how these codes work below. I use the term reader to describe the audience, whether they are viewing, hearing or reading the communication.

Medium: the medium, or material, that the design is applied to carries just as much, if not more, meaning that the actual design. Readers have associations with specific mediums and set expectations of how they should function, interact with as well as read. Marshall McLuan argued that the medium contained all of the meaning in his book, The medium is the message.

Type, space, colour and time: these all help to make up the structural elements of design and can be altered to bring meaning through historical, genre and social class (etc) assumptions.

Image: image, or photography, is also a structural element but within an image several sub-codes can be found by analysing everything from the subject, to the lighting, to the angle. If the subject is a person then there are codes such as body language, facial expression, posture, physical appearance, etc, that all mean something to the reader.

Sound: although not traditionally associated with graphic design, sound has become a popular element in communication design with the use of motion graphics and multimedia. As with image, sound remains a structural element in the design, but contains many sub-codes. The style, sound, volume, rhythm, beat etc all contain meaning for the reader.