Sigma (upper case Σ, lower case σ; Greek Σιγμα, lower case in word-final position ς) is the eighteenth letter of the Greek alphabet, and carries the /s/ sound. In the system of Greek numerals it has a value of 200. When used at the end of a word, and the word is not all upper case, the final form (ς) is used. (e.g. Ὀδυσσεύς (Odysseus) - Note the two sigmas in the center of the name, and the word-final sigma at the end.) Not to be confused with the cedilla ç.
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OMEGA is the premier counter-terrorism unit of Latvia. Founded in 1992, OMEGA cooperates with many other counter-terrorism units over the world. Its equipment and weaponry includes the Heckler & Koch MP5, the HK G36C and the Walther P99.