The .NL has a minimal of 2 characters, the maximum is 63.
Domainnames existing only out of numbers is allowed.
Domainnames are not allowed to start with a hypen (-)
Minimal length of period of registration: 1 year.
Transfer to other registrar possible, if you are the owner.
Transfer to other registrar with new owner, possible with permission of owner and receiver.
This domain extension works with an authorization code.
Change of owner name (possible, however not free of charge).