Explain allowReserved in RFC6570 terms

This aligns allowReserved with style by similarly correlating it
with RFC6570 operators.  This will make it easier to write a more
in-depth explanation of the process in an appendix.

versions/3.0.4.md

@@ -1068,7 +1068,7 @@ Field Name | Type | Description
 ---|:---:|---
 <a name="parameterStyle"></a>style | `string` | Describes how the parameter value will be serialized depending on the type of the parameter value. Default values (based on value of `in`): for `query` - `form`; for `path` - `simple`; for `header` - `simple`; for `cookie` - `form`.
 <a name="parameterExplode"></a>explode | `boolean` | When this is true, parameter values of type `array` or `object` generate separate parameters for each value of the array or key-value pair of the map. For other types of parameters this property has no effect. When [`style`](#parameterStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`.
-<a name="parameterAllowReserved"></a>allowReserved | `boolean` | Determines whether the parameter value SHOULD allow reserved characters, as defined by [RFC3986](https://tools.ietf.org/html/rfc3986#section-2.2) `:/?#[]@!$&'()*+,;=` to be included without percent-encoding. This property only applies to parameters with an `in` value of `query`. The default value is `false`.
+<a name="parameterAllowReserved"></a>allowReserved | `boolean` | When this is true, parameter values are serialized  using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are not allowed in the query string, or have a meaning other than their literal value (e.g. `+` as an escape for the space character in `application/x-www-form-urlencoded` query strings). This property only applies to parameters with an `in` value of `query`. The default value is `false`.
 <a name="parameterSchema"></a>schema | [Schema Object](#schemaObject) \| [Reference Object](#referenceObject) | The schema defining the type used for the parameter.
 <a name="parameterExample"></a>example | Any | Example of the parameter's potential value. The example SHOULD match the specified schema and encoding properties if present. The `example` field is mutually exclusive of the `examples` field. Furthermore, if referencing a `schema` that contains an example, the `example` value SHALL _override_ the example provided by the schema. To represent examples of media types that cannot naturally be represented in JSON or YAML, a string value can contain the example with escaping where necessary.
 <a name="parameterExamples"></a>examples | Map[ `string`, [Example Object](#exampleObject) \| [Reference Object](#referenceObject)] | Examples of the parameter's potential value. Each example SHOULD contain a value in the correct format as specified in the parameter encoding. The `examples` field is mutually exclusive of the `example` field. Furthermore, if referencing a `schema` that contains an example, the `examples` value SHALL _override_ the example provided by the schema.
@@ -1618,7 +1618,7 @@ Field Name | Type | Description
 <a name="encodingHeaders"></a>headers | Map[`string`, [Header Object](#headerObject) \| [Reference Object](#referenceObject)] | A map allowing additional information to be provided as headers, for example `Content-Disposition`.  `Content-Type` is described separately and SHALL be ignored in this section. This property SHALL be ignored if the request body media type is not a `multipart`.
 <a name="encodingStyle"></a>style | `string` | Describes how a specific property value will be serialized depending on its type.  See [Parameter Object](#parameterObject) for details on the [`style`](#parameterStyle) property. The behavior follows the same values as `query` parameters, including default values. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded`.
 <a name="encodingExplode"></a>explode | `boolean` | When this is true, property values of type `array` or `object` generate separate parameters for each value of the array, or key-value-pair of the map.  For other types of properties this property has no effect. When [`style`](#encodingStyle) is `form`, the default value is `true`. For all other styles, the default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded`.
-<a name="encodingAllowReserved"></a>allowReserved | `boolean` | Determines whether the parameter value SHOULD allow reserved characters, as defined by [RFC3986](https://tools.ietf.org/html/rfc3986#section-2.2) `:/?#[]@!$&'()*+,;=` to be included without percent-encoding. The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded`.
+<a name="encodingAllowReserved"></a>allowReserved | `boolean` | When this is true, parameter values are serialized  using reserved expansion, as defined by [RFC6570](https://datatracker.ietf.org/doc/html/rfc6570#autoid-20), which allows [RFC3986's reserved character set](https://datatracker.ietf.org/doc/html/rfc3986#autoid-13), as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including `%` outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are not allowed in the query string, or have a meaning other than their literal value (e.g. `+` as an escape for the space character in `application/x-www-form-urlencoded` query strings).  The default value is `false`. This property SHALL be ignored if the request body media type is not `application/x-www-form-urlencoded`.
 
 This object MAY be extended with [Specification Extensions](#specificationExtensions).