History of the Arabic alphabet the same. After all this, there were only 17 letters that were different in shape. One letter-shape represented 5 phonemes ("b t th n" and sometimes "y"), one represented 3 phonemes ("j ħ kh"), and 5 each represented 2 phonemes. Compare the Hebrew alphabet, as in the table at . A similar ambiguity occurs in the German Fraktur font, in which the Roman alphabet uppercase letters I and J look the same but are officially different letters. The Arabic alphabet is first attested in its classical form in the 7th century. See PERF 558 for the first surviving Islamic Arabic
Morse code are used to indicate changes in communications protocol status or white space text formatting actions. The symbols !, $ and & are not defined inside the ITU recommendation on Morse code, but conventions for them exist. The @ symbol was formally added in 2004. There is no standard representation for the exclamation mark (!), although the KW digraph () was proposed in the 1980s by the Heathkit Company (a vendor of assembly kits for amateur radio equipment). While Morse code translation software prefers the Heathkit version, on-air use is not yet universal as some amateur radio operators in North America