A big restriction in Magento is that it is not possible to use store view codes multiple times for different stores / websites.
For example this should be possible:
But this is not possible, because the store view code must be unique.
Now we have to do something like this:
And this just doesn't make sense.
It would be nice to have the possibility to use store view codes across different websites / stores. Or to rewrite the storeview codes on the frontend, something like this:
code - rewrite to
eng - en
fra - fr
deu - fr
english - en
french - fr
german - de