This includes conventions of movement, which are used to signal particular actions to the audience.
One theory is that a red flag was used to signal the score in the game's early days.
Language can also be used to signal sexual orientation to others.
First, the same conjunction may be used to signal different relations, depending on the context.
These could be used to signal to the horizon, even in conditions of bright sunlight.
The use of model or actual dead birds is used to signal danger to others.
Some letters are also used to signal numbers and mistakes.
At max, it was meant to be used to signal passing aircraft.
A liberty bell cast in 1800 was used to signal the beginning of church service until the 21st century.
Flowers were used to signal meanings in the time when social meetings between men and women was difficult.