National flags

• The Flag of the Great Socialist People's Libyan Arab Jamahiriya is a plain green flag.
• Irish nationalism was traditionally represented with a green flag. The current flag of Ireland
  Flag of Ireland
  The national flag of Ireland is a vertical tricolour of green , white, and orange. It is also known as the Irish tricolour. The flag proportion is 1:2...
  
   is a tricolour with green representing the Irish Catholics, orange representing the Irish Protestants, and white in the middle to represent peace.

Other

• Green Flag
  Green Flag
  Green Flag is a roadside rescue company based in the UK. It was formed in 1971 as the National Breakdown Recovery Club and operated under this name under the ownership of National Car Parks until 1994, when it was renamed Green Flag as a symbolic brand name...
  
   is the name of a motoring assistance company in the UK
• The waving of a green flag indicates the beginning or resumption of an auto race
  Auto Race
  is a Japanese version of motorcycle speedway, but combines gambling added into it and is held on an asphalt course, throughout Japan. It is regulated by the JKA Foundation.A typical Auto Race bike is 599㏄. Autorace is predominantly a gambling sport...
  
  .
• The Green Flag Award
  Green Flag Award
  The Green Flag Award is the benchmark national standard for parks and green spaces in the United Kingdom. The scheme was set up in 1996 to recognise and reward green spaces in England and Wales that met the laid down high standards...
  
   is a mark of conservation effort in the UK
• The Green Flag is a novel written by Sir Arthur Conan Doyle, first published in 1900.