The Union Jack or Union Flag is the national flag of the United Kingdom. While no law has been passed making the Union Flag the national flag of the United Kingdom, it has become one through precedent. The flags of British Overseas Territories, as well as certain sovereign states and regions (particularly in the Commonwealth) that were previously British possessions, incorporate the Union Jack into their own flag designs or have official flags that are derived from the Union Jack. Even if the term Union Jack does derive from the jack flag, after three centuries, it is now sanctioned by use and has appeared in official use, confirmed as the national flag by Parliament and remains the popular term.