Punctuation the marks hierarchically, in terms of weight". Cecil Hartley's poem identifies their relative values: <poem style=margin:4em;> The stop point out, with truth, the time of pause A sentence doth require at ev'ry clause. At ev'ry comma, stop while "one" you count; At semicolon, "two" is the amount; A colon doth require the time of "three"; The period "four", as learned men agree. </poem> The use of punctuation was not standardised until after the invention of printing. According to the 1885 edition of "The American Printer", the importance of punctuation was noted in various sayings by children such as: <poem style=margin:4em;>
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