I just tried posting in a thread pointing the readers to "http //learnopengl.com/" (removed the colon!) as I think it's a nice site for learning opengl. However, the editor just kills the url, even when you edit it in again.

Why does this happen, and how to avoid it? It's quite annoying not being able to paste an url and being sure it gets actually posted.

I have seen this happening with other urls too, eg also from wikipedia. It seems quite random behavior, sometimes they get lost, sometimes they dont.