"Human confirmation" checks if your osC shop is accessed
by human or by robot (script or some other software).
It is useful to prevent automated registrations.
I am sure you've seen it in the net (try to register
with yahoo.com or dot.tk). The script shows a randomly
generated picture with digits. The picture is a little
bit distorted to prevent automatic recognition.
If you're human you will recognize the number and type
it into a text box.
If the number is right the registration will go on as usual,
but if the number ist false or absend the Registrationpage
will show again.
( For this Contrib you must have GD-Lib 1.8+ installed ! )