[Boolbar] Not entirely sure, although I once did have a Lock Cup qualifying match against Catherine where all *comments* were to be made in Haiku form, but the move was not included in this (as according to the standard format of separating move from comment, as practiced on PantsMC).
During my last move for The Furcation Move, Furcation O was a new haiku variation. The initial letters of the haiku formed the first line of a new haiku, so "The old writings read / In there ev'ry ancient hai / And its ku under", as well as being a (slightly odd) haiku, forms the first line "To write a haiku" with it's first letters. I can't remember quite why I came up with it, though it does remind of some very difficult limerick game we had once at !York...