Heraldry

[Sarah]

The art or office of a herald; the art, practice, or science ofrecording genealogies, and blazoning arms or ensigns armorial; also,of marshaling cavalcades, processions, and public ceremonies.

[Magaret]

The study of the design, display, history, and regulation of coats of arms. Dates back to the 13th century but its [precursors] have been around for much longer.
Different countries have their own customs regarding [heraldry].
Some countries such as England and Canada have [heraldic] authorities that regulate coats of arms. The United States has one for the military but not for civilians.
People who study heraldry are called heraldists.

[Mark Zuckerberg]

The system by which coats of arms and other armorial bearings are devised, described, and regulated.