Thanks Jay and Susan. That’s a pretty sneaky little trick there with the Combined View!
Jay, it would be awesome if the custom categories dropped out automatically if nothing was using them; that’s a very intuitive solution! But in the Resources-->Manage Resources section, I checked everything and nothing was using the defunct custom categories, yet they still appeared in the drop down list. I had to kill them via the Combined View trick...maybe something in my manager is screwy?
Or on second thought....maybe ModX just retains those custom categories because it figures: "Hey just because something isn’t associated with anything right
now, it developer may still use this in the
future. If the person really wanted to delete the
entire category, they would have eliminated it via the
Combined View."
So maybe the Combined View method isn’t really a trick at all but something that exists by design!
Thanks for the all the help everyone.