Pilots use it. Military uses it. Government agencies use it. Do you use it? You should at least know it. When communicating via voice, as in telephone, two way radio, etc. without being able to "read ones lips", it can be very important not to confuse an "s" with an "f", or a "b" with a "c". This code has been around for a long time and is utilized by countless government and non-government organizations for communication facilitation. It is easy to learn and essential in many situations that a surveyor may tend to encounter.