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Hey there, Lowercase is fine. Not sure why you would have /nl-nl/ and /nl-en/ though, it's either English or Dutch, right? I've set this up many times before and it works just fine, although it's sometimes a little overkill unless you have the English version of a page ranking higher than the Dutch version in Google.nl for example. I usually find adding these as separate websites in WMT's and setting the target country correctly for each site you shouldn't have any problems. So add http://www.domain.com/nl/ as its own site in WMT and set target country to Netherlands, then add http://www.domain.com/en/ as another site and set its target country to UK. Hope this helps, Goodluck, Woody

Thanks Martijn, I will be emailing you back shortly. Best, Chiaryn