Define _core_ parameter and explain the payload to be returned.

- A boolean [details]{.HTML-Variable} flag indicating that a JSON object

  representing metadata about the _`@context`_, instead of the full content, is

  requested (optional).

- A semantically versioned string [core]{.HTML-Variable} in the form

  **major.minor**, conforming to a version of the NGSI-LD specification. When

  present, a JSON-LD _`@context`_ holding both the user _`@context`_ URL and the

  core _`@context`_ URL is returned (optional).

### 13.4.4 Behaviour

- If [details]{.HTML-Variable} is set to [false]{.HTML-Variable}, or

- if [details]{.HTML-Variable} is set to [true]{.HTML-Variable}, the broker

  shall give back metadata about the _`@context`_ that corresponds to the

  indicated local identifier. It shall give back [ResourceNotFound]{.HTML-Error}

  error if the identifier is not found.

- if [core]{.HTML-Variable} is present, the broker shall return an _`@context`_

  in the form of an array of reference URLs (as defined in the JSON-LD

  specification [n.8] section 3.1). The array shall hold two items - one URL

  reference for the original location of the requested user _`@context`_, and

  one URL for the location of the core _`@context`_.

- Otherwise, if [details]{.HTML-Variable} is set to [false]{.HTML-Variable}, or

  [details]{.HTML-Variable} is not present, the broker shall give back the full

  content of the _`@context`_ that corresponds to the indicated local

  identifier, serving it from its internal storage, if the _`@context`_ that

  back [OperationNotSupported]{.HTML-Error} error if it is of kind

  ["Cached"]{.HTML-Code}. It shall give back [ResourceNotFound]{.HTML-Error} if

  the identifier is not found.

- Otherwise, if [details]{.HTML-Variable} is set to [true]{.HTML-Variable}, the

  broker shall give back metadata about the _`@context`_ that corresponds to the

  indicated local identifier. It shall give back [ResourceNotFound]{.HTML-Error}

  error if the identifier is not found.

### 13.4.5 Output data