French 1949-B 5 francs - open 9 vs closed 9

Can anyone explain what is meant by a closed 9 as opposed to an open 9?  My coin has no gaps in the center of the 9, if that is what is meant by closed.  Or does it mean the area inside the loop of the nine is filled somehow?

Thanks for the help in advance!

Hello.
You will find the difference on my site:
http://monnaiesetvarietes.zxq.net/
http://monnaiesetvarietes.zxq.net/FICHES/France/FRANCE%205%20francs%20lavrillier%20alu.pdf
Michel