Why do I get a WM_CHAR message with char code 3 when I press Ctrl + C?

Question

I have a simple Win32 desktop application listening the keyboard message.
When I press Ctrl + C, I got the following message sequence:

WM_DOWN  Ctrl
WM_DOWN  C
WM_CHAR wParam=3
WM_UP  Ctrl
WM_UP  C

Why do I get a WM_CHAR message whose char code is 3?

MSalters_15416 · Answer

Historical. "C" is the third letter of the alphabet. Ctrl-B is 2.