Editorial updates to the meta-viewport rule (#1822)

* Editorial updates to the meta-viewport rule

* Fix broken test

* Fix typo

Author: WilcoFiers

_rules/meta-viewport-b4f0c3.md

@@ -22,22 +22,23 @@ acknowledgments:
 
 ## Applicability
 
-This rule applies to each `meta` element with a `name` attribute whose value is a [case-insensitive][] match for `viewport` and has a `content` attribute.
+This rule applies to each `content` attribute on a `meta` element with a `name` [attribute value][] of `viewport`.
 
-## Expectation
+## Expectation 1
 
-For each test target, the `content` attribute, whose value is mapped to a list of property/value pairs in a user-agent specific manner, does not:
+For each test target, the [attribute value][] does hot have a `user-scalable` property with a value of `no`.
 
-- specify the property `user-scalable` with a value of `no`; nor
-- specify the property `maximum-scale` with a value of less than 2.
+## Expectation 2
+
+For each test target, the [attribute value][] does not have a `maximum-scale` property with a value less than 2.
 
 ## Assumptions
 
-If any of the following is false, this rule can fail while Success Criteria [1.4.4 Resize text][sc144] and [1.4.10 Reflow][sc1410] can still be satisfied:
+Pages for which any of the following is true may satisfy success criteria Success Criteria [1.4.4 Resize text][sc144] and [1.4.10 Reflow][sc1410], even if the rule results in a failed outcome.
 
-- The [page][] has [visible][] [content][].
-- There is no other [mechanism](https://www.w3.org/TR/WCAG21/#dfn-mechanism) available to resize the text content.
-- The [content][] is not by default rendered in a way that fits in an area of 320 by 256 [CSS pixels][], and needs to reflow to do so.
+- The [page][] has no [visible][] [content][]; or
+- There is another [mechanism](https://www.w3.org/TR/WCAG21/#dfn-mechanism) available to resize the text content; or
+- The [content][] does not need to reflow in order to fit in an area of 320 by 256 [CSS pixels][].
 
 ## Accessibility Support
 
@@ -260,12 +261,12 @@ This viewport `meta` element does not have a `content` attribute.
 </html>
 ```
 
-[case-insensitive]: https://infra.spec.whatwg.org/#ascii-case-insensitive 'ASCII case-insensitive'
 [content]: https://www.w3.org/TR/WCAG21/#dfn-content 'content (Web content)'
 [maximum-scale]: https://www.w3.org/TR/css-device-adapt-1/#min-scale-max-scale 'The initial-scale, minimum-scale, and maximum-scale properties'
 [meta]: https://html.spec.whatwg.org/#the-meta-element 'The meta element'
 [page]: https://www.w3.org/TR/WCAG21/#dfn-web-page-s 'Web page'
 [user-scalable]: https://www.w3.org/TR/css-device-adapt-1/#user-scalable 'The user-scalable property'
+[attribute value]: #attribute-value 'Definition of attribute value'
 [visible]: #visible 'Definition of visible'
 [css pixels]: https://www.w3.org/TR/css3-values/#reference-pixel 'CSS 3 definition, reference pixel'
 [sc144]: https://www.w3.org/TR/WCAG21/#resize-text 'WCAG 2.1 Success Criterion 1.4.4 Resize text'