Morse code thus determines the dot length. It is common to assume that a word is 5 characters long. There are two common typical words: "PARIS" and "CODEX". PARIS mimics a word rate that is typical of natural language words and reflects the benefits of Morse code's shorter code durations for common characters such as "e" and "t". CODEX offers a word rate that is typical of 5-letter code groups (sequences of random letters). Using the word PARIS as a standard, the number of dot units is 50 and a simple calculation shows that the dot length at 20 words per minute
Morse code abbreviations code, Q code, Z code as well as the use of Morse prosigns. The skills required to have efficient fast conversations with Morse comprise more than simply knowing the Morse code symbols for the alphabet and numerals. Skilled telegraphists must also know many traditional International Morse code communications conventions. In the following example of a typical casual Morse code conversation between two stations there is extensive use of such: Morse code abbreviations, brevity codes, Morse procedural signs, and other such conventions. An example casual Morse code (CW) conversation between Station S1 and Station S2 is illustrated in the following paragraphs.