How does Yahoo assign a category?
Yahoo uses the LAST section an item is added to as the category. This is true for both item pages and subsection pages. When you have an item that is in multiple sections, the LAST section you place the item into will be considered the PARENT section and that is what will show in the breadcrumbs trail. To reassign a parent section, go to that section page and "reset" the item as follows:
1. Remove the item ID from the contents and update.
2. Reinsert the item ID back into the contents property and update again.
Now your item will be re-categorized and your site's main CONTENTS page will automatically update.