In art history, the study of the conventional meanings of iconographic art, which is art that is meant to convey some doctrine or traditional story. The iconographer identifies the saints represented on cathedral windows, for example, by noting the tools or animals that were included in the pictures specifically for the sake of identification.
In Eastern Orthodoxy, the church has established an extensive set of rules and guidelines to be used for writing icons, both in general and for particular icons. (Quick note on word usage: icons are not "painted", they are "written." They are also "read" by the viewer, rather than just viewed.) Because the icons communicate theological truth, they are often just as careful to write icons correctly as they would be to compose written doctrines and dogmas. Eastern Orthodox theologians often find it useful to "quote from" or refer to a particular icon when making a point, just as they might cite a document written by an earlier theologian or council. The responsibility of writing icons is often carried out by monks. A saint must be canonized by a synod of bishops before icons of the saint can be written and put into use.
There is a vaguer popular sense of the term: a list of the familiar character types, cliches, and celebrities in a given field.
See also: Icon