Weird, there's no function for counting the number of terms in a vocabulary. Oh well. It's an easy query.

How about if there are no terms in the catalog that the last sentence points to the Add term form for the vocabulary? Then they can add however many they want, even though they have to find the orphaned product list again.

When I made the oprhans list, I thought most people would open each product in a new tab, submit the form and close the tab, and do the next one. But redirecting to that page after the form is submitted is more like the rest of Drupal, so I'll put it in.