There are literally over a couple of thousand types of the "-10%" surcharges to be found. In fact, they are a study all on their own.
In 1946, the Belgian government allowed a 10% discount on mail and this was for domestic as well as for overseas mail. You will also find this surcharge on some Belgian stationery as well.
Also, there are stamps that have the new value figured out for you <G>. These are stamps that have the new value surcharged on the stamp instead of the "-10%". As an example, let's use a 5 Franc stamp - with the 10% taken off, that would be 4,50 Francs and the stamp will have "4.50" on it instead of the usual '-10%" These are still in the same category.
You might want to go in to this site, where I had a listing of the towns beginning with the letter "A" - which is just a smattering of what is out there:
http://www.myphilately.com/frm_view...96&topicid=3Chimo
Bujutsu