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?
They are not the same, but pkpass files often times include a QR Code. Which consists just of some random string, that is displayed as a QR Code by your Wallet App.
For example FossWallet!
As far as I am concerned pkpass seems to be quiet widely spread, whenever there is a Wallet possibility.
If you don’t have a pkpass file but want it to look better than a screenshot you may gibt Catima Wallet a try which allows you to store most types of Barcodes in a Wallet like App.
You could use any QR Scanner to read the data and then create a pkpass file using PassAndroid. Sadly the later one doesn’t seem to be maintained anymore.