BCGControlBar Pro for MFC

The framework sends the BCGM_NEW_TAB message when users click the "new tab" placeholder (which is a dummy tab, located at the end of real tab list. If application supports the "new tab" feature, it should display a new default tab in response to this message).

wParamthis parameter is not used.
lParama pointer to tabbed window (the sender)
Application should return TRUE if it processes this message.

First this message is sent to immediate parent of tab control. If the parent doesn't process this message, it's sent to main frame. If the application processes this message, it should create a new (default) tab.