Proper language translation for MODS XML

[dylex]

Currently the translation layer puts everything in iso639-2 long names, but MODS wants 3-char codes. Maybe the primo output layer should do this? Or XML output layer should un-do it? Or there should be field generator config for it?

[ekate]

I am thinking about it for a while and I am not sure. It's tempting to say let's use configs, but won't it mean that each output layer will have more complex lookups ? Probably it's better just to un-do it for XML layer ?