Thanks for the extra input on this. The feature has been logged as support for international postal codes not just for the Netherlands, so this would likely encompass the values you have noted and many more that can be researched and considered for the feature.
If you have any more suggestions, comments, or request it is a good idea to also check out the wish list area of the forum and our feedback form on the site. The feedback form is located just above the navigation. It never hurts to have more requests and ideas from the users.