In Article 18 of the Law on the National Arms, Flag, and Anthem (Ley Sobre El Escudo, la Bandera y el Himno Nacionales) there is a listing of dates that the Mexican flag is flown by all branches of government. Civilians are also encouraged to display the national flag on these days. Many of the dates listed in the law denote significant events and people that shaped of Mexican identity and the course of its History. There also have been occasions where official flag day notices that been announced in the Official Journal of the Federation, but later revoked. One such case was that November 1 was declared a holiday to hoist the national flag in 1991, but was later removed from the list four years later from another order published in Diario Oficial de la Federación.