We have discussed this issue lately and I have already told you that Mobilkon (the provider of Riing) also provides premium rate numbers on exactly the same range (+423663xxx). That makes it difficult to distinguish which numbers correspond to which service. Those premium rate reffered on the previous article numbers were also +423663 (Liechtenstein ones).
This of course is in line with the topic, which is about rates to FL numbers.
I hope now you understand
P.S. Some months ago I have come across an article where someone discussed especially about poremium rate numbers in Liectenstein and that his phone company had to pay exorbitant rates for calls to Liechtenstein made by their customers. They charged very low for these calls! I have not bookmarked it. If I find it again I will post the URL.