Telegraphy the sense of a system that can transmit arbitrary messages over arbitrary distances. Lines of signalling relay stations can send messages to any required distance, but all these systems are limited to one extent or another in the range of messages that they can send. A system like flag semaphore, with an alphabetic code, can certainly send any given message, but the system is designed for short-range communication between two persons. An engine order telegraph, used to send instructions from the bridge of a ship to the engine room, fails to meet both criteria; it has a limited distance and
Comparison of alphabetic country codes Comparison of alphabetic country codes This is a comparison of the IOC, FIFA, and ISO 3166-1 three-letter codes, combined into one table for easy reference. Highlighted rows indicate those entries in which the three-letter codes differ from column to column. The last column indicates the number of codes present followed by letters to indicate which codes are present (O for Olympic, F for FIFA, and I for ISO) and dashes when a code is absent; capital letters indicate codes which match; lower case letters indicate codes which differ. This list only includes nations or territories that have been assigned at