Flag

A flag is a piece of cloth hung from a pole for signalling (as in semaphore) or to identify the bearer, in this sense also called a standard. A national flag is one of the important official symbols of a nation. The study of flags is known as vexillology.

Some particularly famous or interesting flags are:

• The Union Jack, the national flag of the United Kingdom.
• The Dannebrog, the national flag of Denmark. Also the similar Nordic-cross flags of the other Nordic countries.
• The Stars and Stripes, the national flag of the United States.

Subdivisions of countries frequently have flags. Government agencies, educational or other private institutions also sometimes have flags. The United Nations has a flag. Europe also has a flag (see European flag).

---

In computer science, a variable? that holds a true or false value (see Boolean algebra) is often called a flag.

---

A flag can also be an indicator, as in a "red flag" (a sign that something is amiss).

---

/Talk