- |
  ## Vocabulary resolution

    The schema may designate one or more vocabulary fields which use
    terms defined in the vocabulary.  The vocabulary are the short
    names of all the identifiers in the schema.  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
- |
  ```