I don't know what this is from or why I have it.
It has an F20 key.
What pic.twitter.com/0qOTOMkhjJ

— foone (@Foone) October 1, 2019

You know, F20, for reversing the shield polarity.

F13-F24 keys were present on some keyboards in the 1980s. I know because I remember them. Here’s one that I recall using:

Though I have not seen one in person with the F13-F24 keys for at least 30 years.