Religious symbols, geometric shapes and kanji were commonly used as well. Most consist of a roundel encircling a figure of plant, animal, man-made, natural or celestial objects, all abstracted to various degrees. There are no set rules in the design of a mon. Various kamon on display at Himeji Castle Alternatively, the patron clan may have added elements of its mon to that of its retainer, or chosen an entirely different mon for them. Similar to the granting of the patron's surnames, this was considered a very high honor. Occasionally, patron clans granted the use of their mon to their retainers as a reward. The mon held by the ruling clans of Japan, such as Tokugawa's hollyhock mon and the Emperor's chrysanthemum mon, were legally protected from unauthorized usage. When mon came into conflict, the lower-ranked person sometimes changed their mon to avoid offending their superior. It was considered improper to use a mon that was known to be held by someone else, and offensive to use a mon that was held by someone of a high rank. Rules regulating the choice and use of mon were somewhat limited, though the selection of mon was generally determined by social customs. It was not uncommon for shops, and therefore shop-owners, to develop mon to identify themselves. In cases when none of those were available, they sometimes used one of the few mon which were seen as "vulgar", or invented or adapted whatever mon they wished, passing it on to their descendants. Commoners without mon often used those of their patron or the organization they belonged to. Japanese traditional formal attire generally displays the mon of the wearer. In an illiterate society, they served as useful symbols for recognition. Mon were also adapted by various organizations, such as merchant and artisan guilds, temples and shrines, theater troupes and even criminal gangs. On the battlefield, mon served as army standards, even though this usage was not universal and uniquely designed army standards were just as common as mon-based standards (cf.
Like European heraldry, mon were initially held only by aristocratic families, and were gradually adapted by commoners. It is seen on flags, tents, and equipment. By the 12th century, sources give a clear indication that heraldry had been implemented as a distinguishing feature, especially for use in battle. Mon may have originated as fabric patterns to be used on clothes in order to distinguish individuals or signify membership of a specific clan or organization. Maki-e sake bottle with Tokugawa clan's mon, 18th century, Edo period