termios question, PENDIN option

[Kit Chow]

Does anyone know how the PENDIN c_lflag option is used in SVR.4.0
termio(7)? The description of PENDIN in the manual page is:

	"Retype pending input at next read or input character"

I believe that the C shell file completion code uses this feature.
Any information about PENDIN and how the C shell uses this would be
greatly appreciated.

Kit Chow