Oh! Hooray! That’s what I’d originally thought. I’m 
that this is what happened.
Yeah. That is rather complicated, but I don’t see an easy way around it.
. . . wait
Wait. Wait! Wait!!! Why is that hidden? 
Why not just let people choose any old category as the default from a category pulldown? Why did we call it general_category_id rather than default_category_id? It wouldn’t be a big deal to switch to this much-much-much better solution if you could just select any category as the default.