jeffp,
Lena wrote:
Can you rename the subgroup before deleting it?
That's a good point, and I should have thought of it. In Yahoo Groups (and no doubt Groups.io) renaming a group does not reserve the old name.
If the same holds true for Groups.io subgroups then you could rename the subgroup to something arbitrary before deleting it. That way you can pick any arbitrary name to make non-reusable, leaving the desired name free for reuse.
Shal
Shal Farley