The phrase "green tick" refers to a symbol or mark often used to indicate that something has been approved, completed, correct, or done successfully. It suggests that something has met a certain standard or requirement. Full definition
I will always remember green ticking stripe with affection — the «official» 4 - H uniforms for girls were made up in that. (theletteredcottage.net)
In our experience, you'll need to fiddle with your TV's settings to be greeted with a list of green ticks in the «4K details» troubleshooting menu. (stuff.tv)