These letters were not in use at the same time and place, and this is only a partial list.
The shorthand for 'this' (thorn with a superscript 's') was left out because it doesn't render
correctly
on most systems. Maybe a Windows update will fix it someday.
The long 'ſ' substitution mostly follows the rules for English given here.
It was used in German texts until WWII, where you're much more likely to see it. The rules are a bit
different from English though.
This is kind of useful for troubleshooting character encoding bugs.
Related links: