How to use custom fields as virtual categories

One of the biggest limitations of Joomla's category system is that it doesn't allow you to add a single article/listing to more than one category. Other limitation is that all categories must be setup before you submit articles/listings.

Let's say you want to create a site with restaurants. You might want to create "Restaurants" as the main category and cuisines as subcategories, i.e "American Cuisine", "French Cuisine", "Italian Cuisine", ... But since some restaurants serve more than one cuisine, this solution is not good because Joomla will not allow you to put the same restaurant to more than one cuisine category.

We recommend to create only a single "Restaurant" category without subcategories and use a JReviews custom field to create "virtual" cuisine categories.

If you want the ability to put a listing to more than one "virtual" category, create a Multiple select list or Checkboxes type of custom field, otherwise you can also use Single select or Radiobuttons field types.