--- Track all existing categories. Something is a category if 1) it has an en-
--- try somewhere in categorylinks, or 2) it once did. Categories might not
--- have corresponding pages, so they need to be tracked separately.
+-- Track all existing categories. Something is a category if 1) it has an entry
+-- somewhere in categorylinks, or 2) it has a description page. Categories
+-- might not have corresponding pages, so they need to be tracked separately.