Select Category
By default, category selection is singular. That is why there is a drop-down field to select a category. This should be the standard-setting. Because according to Google Webmaster Guidelines and other SEO and UX best practices, it is recommended to have only one category assigned to a product. If you need to show your products based on multiple factors or for searching or sorting feature, you can use tags.
Vendors need to select the category from the drop-down.
