Green flag

A green flag has various meanings.

National flags

 * The Flag of the Great Socialist People's Libyan Arab Jamahiriya was a plain green flag.
 * The Flag of Saudi Arabia has a field of green, which represents Islam.
 * Irish nationalism was traditionally represented with a green flag. The current flag of Ireland is a tricolour with green representing the Irish Catholics, orange representing the Irish Protestants, and white in the middle to represent peace.
 * The former Flag of Mauritania.
 * Various green-striped American flags flew during the Revolutionary War, with green representing the 'color of hope'.

Other

 * A green flag is part of a set of racing flags and indicates the beginning or resumption of an auto race.
 * The actual flags flown in parks and gardens that have received the Green Flag Award.
 * On rail transport in Great Britain and Ireland, green flags are sometimes used (less often than in the past) by railway guards as a signal to engine drivers that they can proceed.