Non-verbal communications are those that do not take voice to communicate with. They can be very basic, such as a billboard on the side of the road, or somewhat complex such as a textbook. The messages can be overt such as an "open for business" sign, or more covert, such as a chalk mark that looks like simple graffiti.
Types of Non-verbal communication
- Military Hand Signals are a common form displayed in many movies, and are highly effective. Sign language is another, and there are dialects in all parts of the world.
- Morse Code is a non-verbal digital communications mode which can be used with radio, light signals, tapping on a wall, or even blinking.
- Radio Data is a digital transmission mode for radios which can convey anything from text chat, files, email, or even provide a network.
Another form is what some college dorm students do when they have company over by putting a sock or clothes hanger on the door to signal to their room mate that they are busy and that they should come back later. This can also be used to indicate whether or not it is safe to stop by.
Robert Hannsen while working for the FBI sold secrets to the Russian government. When he would place the information in the park for collection, he would make a chalk mark on a sign in a specific orientation. This would signal to the other operative that the 'dead drop' contained information. They would then collect the information and leave a bag of money for him (although he seemed to prefer payment in diamonds) and they would make a different mark indicating that payment was ready to be collected. Usually the first mark is a / and the second is a \ making an X. This is a common protocol displayed in many movies and TV series.
Warchalking is a method people are using to indicate open wifi access points. They make a particular mark in chalk on a building or sidewalk when they discover an open access point. Anyone who knows the mark then knows they can get internet access at that point.
US colonists used lamps to indicate how the British would be attacking, "1 if by land 2 if by sea". This not only indicated what route was being used, but when the attack was to occur.
Signs are a method of non-verbal communication to inform people of directions, business hours, road hazards, and other things that someone thinks will be important for people to know.
FEMA will mark an X on a door which indicates the date the building was cleared, how many dead and how many alive were located within that building.
There are many other forms, some instantly convey the information, others are latent and only convey information when the right person happens upon them. It is important to think about ways that you can communicate and work out signals with your team members ahead of time. Selecting the correct set of symbols can be an important tool in your arsenal of communications skills.