Last time, I was at the office when my friend John, who is a big fan of riddles and traveling, came up to me with a sly smile and a little piece of paper in his hands.
"Hey, you like to hang around on PSE, right?
-Yes, what do you want? You're afraid of introducing yourself on this website? Poor little thing.
-Shut up already, and solve me this. What is the link between the countries written on that paper?
-Oh, a puzzle? Nice, let me think a bit about it...
-Just before you start, I can tell you that Germany and Morocco don't share the link either, but Slovenia does."
Here are the countries I found on the paper :
Can you help me to find the link between these countries?
Edit (I hope this edit and the new hint will narrow this puzzle. I will drop another one later): My friend John just contacted me, and told me that these countries also share the link :
He also told me that these ones don't share the link :
Switzerland (talking about red and white...)
Hint (it has changed!) :
My friend John and I are working in IT. You could say we are sort of webmasters, and we spend much time on the Internet.