arcpy - Adding parameters to category in Python Script Tool?

There is plenty of documentation on how to add parameters to a category in a Python Toolbox i.e. see the bottom of http://resources.arcgis.com/en/help/main/10.1/index.html#/Defining_parameters_in_a_Python_toolbox/001500000028000000/)

But I haven't found a way to do this for a Python Script Tool. Can this be done?

Answer

Yup, you need to use the Tool Validator. See this help link: http://resources.arcgis.com/en/help/main/10.1/index.html#/Programming_a_ToolValidator_class/00150000000v000000/

def initializeParameters(self):

  self.params[4].category = "Options"
  self.params[5].category = "Options"
  self.params[6].category = "Advanced"
  self.params[7].category = "Advanced"