Advanced taxonomies: using hierarchies

For many users needing simple classification schemes, the examples above may be the only structure necessary for tagging site content. For more elaborate classification needs, consider the hierarchy option when creating vocabularies. Hierarchies allow the creation of sophisticated taxonomies with categories and subcategories in a tree structure, much like Yahoo categories or subject classifications used by libraries.

For example, the vocabulary Food could include the following categories and subcategories:

• Dairy
  • Milk
• Drink
  • Alchohol
    • Beer
    • Wine
  • Pop
  • Milk
• Meat
  • Beef
  • Chicken
  • Lamb
• Spices
  • Sugar

Note that the term Milk appears within both Dairy and Drink. This is an example of multiple parents for a term. Just select both parents when creating the term Milk.

Don't forget that that the order of term siblings (e.g. Beef, Chicken, Lamb) can be controlled with the weight option.