So I'm only on my phone but this is the definition of corporal punishment that came up when I searched (will look further into it when kids are in bed and I'm on the computer)
No flogging or beating in this house
From wiki - "any punishment in which physical force is used and intended to cause some degree of pain or discomfort, however light."
I don't intend to cause pain or discomfort and rarely do. 2yo usually laughs at me when I do smack his bum but yet will respond when given the choice between a smack or doing as he's asked.