Tagging: Separate Form and Function

In 4.7.*, the name tagging refers to both "form" and "function". It's better to separate them. Let me be more specific.

When a new vocabulary is created, users can define that vocabulary to be a "tag", by checking the tagging checkbox. This specification has a form implication and a function implication.

Form: when users created new nodes associated with the vocabulary, there is an autocomplete textfield that allows users to specify which terms in the vocabulary to classify the node with.

Function: users can create new terms, which haven't existed yet.

Both of these implications are great for tagging, or folksonomy, which supposedly have many terms and allow users to create new terms. However, when form and function are separated, the good old "controlled" vocabulary can benefit too.

How can they be separated? Well, tag = autocomplete textfield + user created terms. So, instead of one option "tag" to define a vocabulary, have two check-box options: (1) autocomplete text field, and (2) user created terms.

How does such a separation benefit taxonomy? A controlled vocabulary can have *many* terms. An autocomplete text field, instead of a long list of terms, should help useability greatly.

Furthermore, the two concepts "control vs folksonomy" and "hierarchy vs flat" should *not* be mutually exclusive. It makes perfect sense to have a hierarchical folksonomy: terms can have parents/children and at the same time users can add new terms to the vocabulary.

So, I think separating form and function in "tagging" can help a lot.