At present, there is a set of email templates for the tracker that is the same templates are used for all module instances. Since instances can be used for quite different tasks (cf. CONTRIB-811), it may be suitable to provide an option to customize those emails for a given instance.

I imagine having an interface similar to defining additional elements in the tracker or templates in the database module. A set of standard templates in different languages could be provided in distro as the default set.

The only issue to resolve is whether to use multilang filter to handle content in different languages or whether to have a separate item for each supported language. I guess this may depend whether these are stored in the database (filter would probably be simpler to handle) or as text files (separate files for each language would probably be simpler to handle).