Comma titles that follow a name: "John Smith, Ph.D." Similarly in lists that are presented with an inversion: "...; socks, green: 3 pairs; socks, red: 2 pairs; tie, regimental: 1". Commas may be used to indicate that a word, or a group of words, has been omitted, as in "The cat was white; the dog, brown." (Here the comma replaces "was".) Commas are placed before, after, or around a noun or pronoun used independently in speaking to some person, place or thing: In his 1785 essay "An Essay on Punctuation", Joseph Robertson advocated a comma between the subject and predicate of
Comma signified by a dot at the bottom, middle, or top of the line. For a short passage (a "komma"), a "media distinctio" dot was placed mid-level ( · ). This is the origin of the concept of a comma, although the name came to be used for the mark itself instead of the clause it separated. The mark used today is descended from a diagonal slash, or "virgula suspensiva" ( / ), used from the 13th to 17th centuries to represent a pause. The modern comma was first used by Aldus Manutius. In general, the comma shows that the words