Morse code abbreviations Morse code are formed. From 1845 until well into the second half of the 20th century, commercial telegraphic code books were used to shorten telegrams, e.g. "Pascoela = Natives have plundered everything from the wreck". The following Table of Morse code abbreviations and further references to Brevity codes such as the Q code, Z code and R-S-T system serve to facilitate fast and efficient Morse code communications. To make Morse code communications faster and more efficient, there are many internationally agreed patterns or conventions of communication which include: extensive use of abbreviations, use of brevity codes such as the RST
Letter frequency xz. Modern International Morse code (generally believed to have been developed by Alfred Vail based on English-language letter frequencies of the 1830s) encodes the most frequent letters with the shortest symbols; arranging the Morse alphabet into groups of letters that require equal amounts of time to transmit, and then sorting these groups in increasing order, yields e it san hurdm wgvlfbk opxcz jyq. Similar ideas are used in modern data-compression techniques such as Huffman coding. Letter frequency was used by other telegraph systems, such as the Murray Code. Letter frequencies, like word frequencies, tend to vary, both by writer and