Add examples. Define value only.

- Replace the existing Attribute value instance with the Value Fragment

  provided.

  - If a user _`@context`_ has been supplied, the Value Fragment shall undergo

    expansion prior to replacement (see clause 8.2.4)

  - If the Attribute value to be replaced is represented in a simplified

  - If the Attribute value to be replaced is represented in the **value only**

    representation, the _`type`_ of any pre-existing Attribute in the target

    entity shall be preserved.

  - If a user _`@context`_ has been supplied, the Value Fragment shall undergo

    expansion prior to replacement (see clause 8.2.4)

  - If the Attribute whose value is to be set previously contained an

    _`observedAt`_ sub-Attribute and no _`observedAt`_ element can be found

    within the Value fragment then:

    _`observedAt`_ sub-Attribute and the value to be replaced is represented in

    the **value only** representation:

    - if an _`observedAt`_ timestamp is defined, then the _`observedAt`_

      sub-Attribute is updated using the timestamp supplied.

#### 10.4.4.5 Output data

A JSON or JSON-LD document representing an NGSI-LD Value Fragment as mandated by

clause 5.5. formatted according to the defined representation.

clause 5.5, formatted according to the defined representation.

if an _`@context`_ is supplied and the returned Attribute corresponds to a

[VocabProperty]{.HTML-Keyboard}, the returned value shall be compacted according

## 5.5 NGSI-LD Value fragments

When updating the value of an individual NGSI-LD Attribute, it is necessary to

have a means of describing the value to be updated.

When updating or retrieving the value of an individual NGSI-LD Attribute, it is

necessary to have a means of describing the value to be updated. The value

_`null`_ or an NGSI-LD Null are prohibited within NGSI-LD Value fragments.

A Value Fragment in the normalised format, shall at a minimum be a JSON Object

holding the mandatory elements of an Attribute as described in clause 5.3.2.2 -

i.e. ["type"]{.HTML-Code} and one of ["value"]{.HTML-Code},

["object"]{.HTML-Code}, ["languageMap"]{.HTML-Code}, ["vocab"]{.HTML-Code},

["valueList"]{.HTML-Code}, ["objectList"]{.HTML-Code} or ["json"]{.HTML-Code}.

Further members where present, shall follow the data types described in clause

5.2.6.4.8 and an optional. ["@context"]{.HTML-Code} may also be present.

Further members (such as ["datasetId"]{.HTML-Code}, ["observedAt"]{.HTML-Code})

where present, shall follow the data types described in clause

5.2.6.4.8. An optional ["@context"]{.HTML-Code} may also be present.

<!-- prettier-ignore-start -->

>>> [!tip] EXAMPLE 1:

Representation of an NGSI-LD Value Fragment of a _Property_ in the

**normalised format**:

```json

{

  "value": "Berlin",

  "type": "Property",

  "observedAt": "2022-03-14T12:51:02.000Z",

  "@context": "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context-v1.9.jsonld"

}

```

>>>

<!-- prettier-ignore-end -->

A Value Fragment in the concise format, shall be a JSON Object compacted

according to the Normalized-to-Concise Compaction algorithm found in clause

undergo full compaction if the property value is a JSON primitive or GeoJSON

object, so that the ["value"]{.HTML-Code} element shall remain within the Fragment

A Value Fragment in the simplified format, shall consist of a JSON

representation of Attribute value alone. the value _`null`_ or an NGSI-LD Null

are prohibited.

<!-- prettier-ignore-start -->

>>> [!tip] EXAMPLE 2:

Representation of an NGSI-LD Value Fragment of a _Property_ in the

**concise format**:

```json

{

  "value": "Berlin",

  "observedAt": "2022-03-14T12:51:02.000Z",

  "@context": "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context-v1.9.jsonld"

}

```

>>>

<!-- prettier-ignore-end -->

A Value Fragment in the simplified format, shall consist of a JSON Object

holding a representation of the Attribute value alone, and following the

compaction rules of the concise representation described above. An

["@context"]{.HTML-Code}, and in the Multi-attribute case ["datasetId"]{.HTML-Code}

may also be present.

<!-- prettier-ignore-start -->

>>> [!note] NOTE:

>>> [!tip] EXAMPLE 3:

When an optional user _`@context`_ is supplied using a mechanism appropriate

to the binding used, Value Fragments represented in the normalised and concise

formats are valid JSON-LD documents.

Value Fragments represented in the simplified format are valid JSON documents.

Use of a supplied user _`@context`_  is implied.

Representation of an NGSI-LD Value Fragment of a _Property_ in the

**simplified format**:

```json

{

  "value": "Berlin",

  "@context": "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context-v1.9.jsonld"

}

```

>>>

<!-- prettier-ignore-end -->

When updating the value of an individual NGSI-LD Attribute, it shall be assumed

that Entity [id"]{.HTML-Code}, Entity ["type"]{.HTML-Code} and Attribute name

can all be determined from the operation signature.

When updating or retrieving the value of an individual NGSI-LD Attribute, it shall

be assumed that Entity [id"]{.HTML-Code}, Entity ["type"]{.HTML-Code} and Attribute

name can all be determined from the operation signature.

Where the binding explicitly defines a request or response to be **value only**,

the NGSI-LD Value Fragment shall be represented purely as a value (e.g. a JSON Primitive)

rather than as a JSON Object.

<!-- prettier-ignore-start -->

>>> [!tip] EXAMPLE 4:

Value only Representation of an NGSI-LD Value Fragment

```json

"Berlin"

```

>>>

<!-- prettier-ignore-end -->