Mullet (heraldry) in the context of Coat of arms of the Washington family

The flag of Washington, D.C., consists of three red stars above two red bars on a white background. It is an armorial banner based on the coat of arms granted to Lawrence Washington (George Washington's 3rd great-grandfather) of Sulgrave Manor Northamptonshire, England, in 1592. This coat of arms was used privately by the president in his home at Mount Vernon. In heraldry, the stars are called mullets and the coat of arms is blazoned as argent two bars gules, in chief three mullets of the second.

In 1938, the District Flag Commission was created by an Act of Congress "to procure a design for a distinctive flag for the District of Columbia". The District Flag Commission was composed of three non-elected federally-appointed members: the president of the Board of Commissioners, the secretary of war and the secretary of the Navy. The flag was selected by the commission with the help of the Commission of Fine Arts. Since no local group was involved in the selection process, Washingtonians saw the flag as a symbol of their lack of representation. More recently, it has been embraced by most DC residents and businesses, as well as the DC Statehood Movement as a symbol of their local identity in the 21st century.

In heraldry, cadency is any systematic way to distinguish arms displayed by descendants of the holder of a coat of arms when those family members have not been granted arms in their own right. Cadency is necessary in heraldic systems in which a given design may be owned by only one person at any time, generally the head of the senior line of a particular family.

As an armiger's arms may be used 'by courtesy', either by children or spouses, while they are still living, some form of differencing may be required so as not to confuse them with the original undifferenced or "plain coat" arms. Historically, arms were only heritable by males, and therefore cadency marks had no relevance to daughters; in the modern era, Canadian and Irish heraldry include daughters in cadency.