majdi Achouri:
The idea is to use the Language_xxx.properties to specify the (key, Value) which will be printed in the interface of each customer.
While you'd end up with different Language.properties anyway, I'd organize them in a different way than you propose:
You can override translations for each module from another module - the original module doesn't need to be a Liferay core module for that. So you can write your original portlet and provide it with a generic translation, then have 3 more projects, each with a customer specific translation that overrides the original module's translation. You'd end up delivering one of these 3 projects to each customer - name the modules by customer, and you'll easily have an overview over what goes where, and are 100% on the beaten paths, no extra code, great maintainability.
