2006 New York Code - Visual Notification.

 
  § 33-1003. Visual notification.
    1.  All  persons  providing  commercial  lawn  application shall affix
  markers to be placed within or along the perimeter  of  the  area  where
  pesticides will be applied. Markers are to be placed so as to be clearly
  visible  to  persons immediately outside the perimeter of such property.
  Such markers shall be posted at least twelve inches above the ground and
  shall be at least four inches by five inches in size.
    2. The markers required pursuant to this section shall be in place  on
  the  day  during which the pesticide is being applied and shall instruct
  persons not to enter the property and not to  remove  the  signs  for  a
  period  of at least twenty-four hours. Such instruction shall be printed
  boldly in letters at least three-eighths of an inch in height.