So can I, Dave. After some research I found out that there is an actual name of this breed now in English "African".
http://www.entente-ee.com/deutsch/s...ssgefl%FCgel/BDRG/Afrikanische%20H%F6cker.pdf
But it´s still "Anser cygnoides f. dom." and not "Anser cygnoides", even when it descended from the wild species.
BTW, your information about the dewlap is not correct. Older geese of the Chinese Goose are allowed to show a dewlap. Only a double dewlap is considered a coarse error/mistake!
Source: Current Standard of pure breed poultry for Europe
And a slight failure in the birds shape/appearance doesn´t disqualify it from belonging to the breed. It´s just punished with a deduction of points.
Or do you consider a eg. Mercedes with a scratch on the bonnet not a Mercedes?