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 that is the beginning of the definition of onPaint() I have seen commented out argument names used to avoid "unreferenced formal parameter" compiler warnings (these warnings will only appear at a high warning level, level -W4 for Microsoft compilers).