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
Morse code abbreviations the same as the prosign for "end of telegram", and the widely used but non-ITU "Over to you only" prosign is the official code for open parenthesis [(] or "left bracket". The listener is required to distinguish the meaning by context. In the example casual conversation between two station operators, above, the Morse transmissions in the grey boxes show the equal sign [=] in the same way that a simple electronic automatic Morse code reader with a one- or two-line display does: It can't distinguish context so it always displays the math symbol. It would also display an open parentheses