Serial comma toast. Adding a serial comma removes this ambiguity. Writers who normally avoid the serial comma often use one in these circumstances, although sometimes re-ordering the elements of such a list can help as well. In some circumstances using the serial comma can create ambiguity. If the book dedication above is changed to the serial comma after "Ayn Rand" creates ambiguity about the writer's mother because it uses punctuation identical to that used for an appositive phrase, leaving it unclear whether this is a list of three entities (1, my mother; 2, Ayn Rand; and 3, God) or of only two
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