The most common variation from the three-line standard is one line, sometimes called a monoku. It emerged from being more than an occasional exception during the late 1970s.Van den Heuvel, Cor. The Haiku Anthology 2nd edition. Simon & Schuster 1986. p10 The one-line form, based on an analogy with the one-line vertical column in which Japanese haiku are often printed, was lent legitimacy principally by three people:
