qr code is the squares code that, if used with a qr code scanner redirects me automatically to a website or to download a pkpass file, right?

after downloading said pkpass file to my android, any wallet application like fosswallet should recognize it and add it to the local library (on my android device), right?

what other formats do transportation authorities use?

To those residing in Germany, is pkpass use widespread there? What are common formats used there?