# Tag

> Tags, or folksonomy, are metadata attached to items for classification and retrieval. Unlike directory-based classification, where an item must go in just one folder, they let you attach multiple tags to a single item.

Tags, or folksonomy, are metadata attached to items for classification and retrieval. Unlike directory-based classification, where an item must go in just one folder, they let you attach multiple tags to a single item.

Sometimes the set of available tags is restricted (controlled vocabulary), but usually people are free to use arbitrary tags (uncontrolled vocabulary).

## See also

- [Faceted classification](https://wiki.g15e.com/en/pages/Faceted%20classification.txt)