I'll reply to your point, but this has been discussed in length in these forums and I doubt that any of us will say something new. 
I'm sure you'll find those topics easily.
That would be tel:+43-1-559-8547 or something like that depending on the context. Just like mailto:vv01f@example.com
tel:// or mailto:// wouldn't and shouldn't work.
bitcoin:15VjRaDX9zpbA8LVnbrCAFzrVzN7ixHNsC?amount=1&label=Faucet&message=Donation
Keep in mind that these schemes are mainly meant for parsers. That's also why standards are important.
I'm sure you'll find those topics easily.
one downside I thought of: Users have easily to understand it - like tel://0043155985476 - the know http:// from the web, and they know telephone-numbers, easy
That would be tel:+43-1-559-8547 or something like that depending on the context. Just like mailto:vv01f@example.com
tel:// or mailto:// wouldn't and shouldn't work.
plz post an example thats of the same ease for the sending of some btc to a specific address - just to focus on the topic and not just slapping each other
bitcoin:15VjRaDX9zpbA8LVnbrCAFzrVzN7ixHNsC?amount=1&label=Faucet&message=Donation
Keep in mind that these schemes are mainly meant for parsers. That's also why standards are important.