An application uses frame-control flags in WinCreateStdWindow to specify which frame controls to give to the frame window. Frame-control flags are constants that have the FCF_ prefix.

The frame-window class (WC_FRAME), like other public window classes, provides many class-specific window styles that applications can use to adapt the appearance and behavior of a frame window. To specify the frame-window styles, an application can use either frame-control flags or the frame-window style constants, which have the FS_ prefix. Each style constant has a corresponding frame-control flag. Both produce exactly the same styles in a frame window. Typically, if an application is creating a frame window that uses frame controls, the application uses frame-control flags to specify the frame-window styles-if not, the application uses frame-style constants. An application can combine the frame-style constants with the standard window styles when creating a frame window.

When an application calls WinCreateStdWindow without setting any frame-control flags, the function creates a standard window that is invisible and behind all its sibling windows, has a width and height of 0, and is positioned at the lower-left corner of its parent window. After the call to WinCreateStdWindow returns, the application can use WinSetWindowPos to change the window's size, coordinates, z-order position, and visibility.

If an application calls WinCreateStdWindow with the FCF_SHELLPOSITION frame-control flag, the function creates the window so that it is in front of its sibling windows and has a standard size and coordinates determined by the system.