Why comment parameter names rather than leave it as it is

Question

Sometimes I see code like this:

LRESULT OnPaint(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/)

Why comment pa

Answer 1

If the called function (OnPaint in your example) do not use the arguments, the coder can avoid warning messages about unused arguments when compiling by not providing argument names.