American Morse code standard for U.S. landline telegraph companies, including the dominant company, Western Union, in part because the original code, with fewer dashes, could be sent about 5% faster than International Morse. American Morse also was commonly used for domestic radio transmissions on the Great Lakes, and along the Atlantic and Pacific coasts. However, International Morse predominated for ocean-going vessels, and many U.S. shipboard operators became skilled in transmitting both versions of the Code as needed. As already mentioned, American Morse is less suitable for use on cables because of the high density of dots. However, this same feature, together with the
Morse code abbreviations head, instead of writing text on paper or into a computer file, the receiving operator copying mentally will interpret the prosign for either a mental pause, or to jot down for later reference a short word or phrase from the information being sent. "Rag chewer" is a name applied to amateur radio Morse code operators who engage in informal Morse code conversations (known as "chewing the rag") while discussing subjects such as: the weather, their location, signal quality, and their equipment. Meaningful rag chewing between fluent Morse code operators having different native languages is possible because of a common language