- |
  ## Vocabulary resolution

    The schema may designate one or more vocabulary fields which use terms
    defined in the vocabulary.  Processing must resolve vocabulary fields to
    either vocabulary terms or absolute URIs by first applying the link
    resolution rules defined above, then applying the following additional
    rule:

      * If a reference URI is a vocabulary field, and there is a vocabulary
      term which maps to the resolved URI, the reference must be replace with
      the vocabulary term.

  ### Vocabulary resolution example

  Given the following schema:

  ```
- $include: vocab_res_schema.yml
- |
  ```

  Process the following example:

  ```
- $include: vocab_res_src.yml
- |
  ```

  This becomes:

  ```
- $include: vocab_res_proc.yml
- |
  ```