How can I delete a subkey that has no USAGE assigned to it?

[stebe at mailbox.org]

> Hi,
> 
> I have generated a new pub key with several subkeys following (1). 
> Is there a way to delete this subkey? 

Yes, indeed. I guess I found it in my dreams, i.e. when I woke up, it came
to my mind that it might be simply N for number...

> (1)https://wiki.fsfe.org/Card_howtos/Card_with_subkeys_using_backups

Stebe