Morse code encoded the same way (A, O, E, I, T, M, N, R, K, etc.). Bulgarian alphabet contains 30 characters, which exactly match all possible combinations of 1, 2, 3, and 4 dots and dashes. Russian requires 1 extra character, "Ы" which is encoded with 5 elements. During early World War I (1914–1916), Germany briefly experimented with 'dotty' and 'dashy' Morse, in essence adding a dot or a dash at the end of each Morse symbol. Each one was quickly broken by Allied SIGINT, and standard Morse was restored by Spring 1916. Only a small percentage of Western Front (North Atlantic
Prosigns for Morse code In the early decades of telegraphy many operating efficiency improvements were incorporated into telegraph operations, including the introduction of Morse symbols known as "procedure signs" or "prosigns". Prosigns were not defined by the inventors of Morse code, but were gradually introduced over time, and greatly improved the speed and performance of daily high-volume message handling operations. Improvements to the legibility of formal written telegraph messages (telegrams) by means of white space formatting were thus supported by the creation of the additional new procedure symbols. Mastery of these special Morse code prosigns is an important part of becoming a fluent and