In MySQL Workbench 6.3, how do I create a ZERO to MANY relationship?

Yes, I know this question has been asked here:

http://stackoverflow.com/questions/25086363/how-to-create-a-zero-or-one-to-many-relationship-in-mysql-workbench

However, at least in MySQL Workbench 6.3, there is no 'NN' check-box under the Foreign Keys tab. Therefore, the answer given is inadequate.