Defacement (flag)

The British Blue Ensign
The flag of Australia, a defaced British Blue Ensign
The former flag of Hong Kong (1959–1997), a defaced British Blue Ensign
The bicolor flag of Indonesia
The flag of Singapore, a defaced Indonesian bicolor flag
The tricolor flag of Colombia
The flag of Ecuador, a defaced Colombian tricolor flag
The tricolor flag of Serbia
The former flag of Montenegro (1905–1918), a defaced Serbian tricolor flag

In vexillology, defacement is the addition of a symbol or charge to a flag. For example, the Australian flag is the British Blue Ensign defaced with a Southern Cross in the fly.

In the context of vexillology, the word "deface" carries no negative connotations, in contrast to general usage. It simply indicates a differentiation of the flag from that of another owner by addition of elements. For example, many state flags are formed by defacing the national flag with a coat of arms.