Sissy is a term used to define a man who crossdresses as a younger woman rather than the traditional crossdresser. Mostly they are into the humiliation side of being forced to dress as a woman. This separates them from traditional crossdressers, as they see themselves liberating a hidden side and see it as empowering rather than a humiliating event.
Adult Babies and Diaper Girls
Some rubber and plastic fetishists have an affinity for diapers and rubber pants. In the case of disposable diapers, this attraction would be to their crinkly plastic backing. In the case of cloth diapers, it would be towards the latex or pvc of the pants worn over them.