The full stop glyph is also used for other purposes. It is often placed after an initial letter used to stand for a name, and sometimes placed after each individual letter in an initialism (for example, "U.S.A."; see Acronym#Punctuation). It also has multiple contexts in mathematics and computing, where it may be called dot or point (short for decimal point).
The full stop symbol derives from the Greek punctuation introduced by Aristophanes of Byzantium in the 3rd centuryBC. In his system, there were a series of dots whose placement determined their meaning. The full stop at the end of a completed thought or expression was marked by a high dot ⟨˙⟩, called the stigmḕ teleía (στιγμὴ τελεία) or "terminal dot". The "middle dot" ⟨·⟩, the stigmḕ mésē (στιγμὴ μέση), marked a division in a thought occasioning a longer breath (essentially a semicolon) and the low dot ⟨.⟩, called the hypostigmḕ (ὑποστιγμή) or "underdot", marked a division in a thought occasioning a shorter breath (essentially a comma). In practice, scribes mostly employed the full stop; the others fell out of use and were later replaced by other symbols. From the 9th century, the full stop began appearing as a low mark instead of a high one; by the advent of printing in Western Europe, the low mark was regular and then universal.