I do not believe that Greece is an isolated market. To my knowledge, Greece is included in the EUR releases. I am not all-knowing but i cannot believe that you have a manual with those codes. I've never seen a Greek only release for SNES.
I am aware only of Germany, Scandinavia, Italy, France, Spain and the UK. I'm sleepy so did i forget anyone? All other countries receive the EUR copy of games.
edit: other codes can be found, such as Mexico, but Mexico is not a European nation. We are talking about Europe. Specifically Nintendo of Europe which has its headquarters in Deutschland.