I tested over in the sandbox some wiki-formating, as signing with tildes was impossible in the thread (now) just below.
Some things are possible, some get automagically nowiki-tags around them. All gets weird once you edit, as this stupid software inserts tabs or such at the beginning some lines (it's already in some phab afaik, why this simple task is still not solved is beyond comprehension).
Ah, and one other thing: There is a link called "Vorschau" (Preview) beneath this box (yes, I don't use VE but the normal editor, without any buttons), but it doesn't really gets me to a preview, it just switches to VE, that's something completely different.