Editorial: target size 'equivalent' understanding doc update (#3735)

closes #3714 - minor rewording for the text that re-explains the
'Equivalent' exception.

specifically changing the text "meet the minimum size" to "meet the
requirements of this Success Criterion", to better match the normative
text.

While editing this, I noticed that the explanation referred to itself by
saying '...the "Equivalent" exception."
The essential exception explanation similarly referred to itself but it
didn't capitalize essential or put it in quotes. So I changed that to
make these self-referring instances consistent.

---------

Co-authored-by: Mike Gower <mikegower@gmail.com>

Author: scottaohara

understanding/22/target-size-minimum.html

@@ -30,10 +30,10 @@ <h3>Exceptions</h3>
 
             <ul>
                 <li><strong>Spacing:</strong> Undersized targets (those less than 24 by 24 CSS pixels) are positioned so that if a 24 CSS pixel diameter circle is centered on the <a>bounding box</a> of each, the circles do not intersect another target or the circle for another undersized target.</li>
-                <li><strong>Equivalent:</strong> In cases where a target does not have a size equivalent to 24 by 24 CSS pixels, but there is another control that can achieve the underlying function that <em>does</em> meet the minimum size, the target can be excepted based on the "Equivalent" exception.</li>
+                <li><strong>Equivalent:</strong> In cases where a target does not have a size equivalent to 24 by 24 CSS pixels, but there is another control that can achieve the underlying function that <em>does</em> meet the requirements of this success criterion, the target can be excepted based on the "Equivalent" exception.</li>
                 <li><strong>Inline:</strong> The success criterion does not apply to inline targets in sentences, or where the size of the target is constrained by the line-height of non-target text. This exception is allowed because text reflow based on viewport size makes it impossible for authors to anticipate where links may be positioned relative to one another. Applying this success criterion when multiple links are embedded in blocks of smaller text often results in an undesirable design. It is more important to set the line height to a value that improves readability.</li>
                 <li><strong>User agent control:</strong> Browsers have default renderings of some controls, such as the days of the month calendar in an <code>&lt;input type="date"&gt;</code>. As long as the author has not modified the user agent default, the target size for a <q>User agent control</q> is excepted.</li>
-                <li><strong>Essential:</strong> If the size and spacing of the targets is fundamental to the information being conveyed, the <q>Essential</q> exception applies. For example, in digital maps, the position of pins is analogous to the position of places shown on the map. If there are many pins close together, the spacing between pins and neighboring pins will often be below 24 CSS pixels. It is essential to show the pins at the correct map location, therefore the Essential exception applies. A similar example is an interactive data visualization where targets are necessarily dense. Another example is where jurisdictions legally require online forms to replicate paper forms, which can impose constraints on the size of targets. In such jurisdictions, any legal requirement to replicate small targets can be considered essential. When the essential exception is applicable, authors are strongly encouraged to provide equivalent functionality through alternative means to the extent practical.</li>
+                <li><strong>Essential:</strong> If the size and spacing of the targets is fundamental to the information being conveyed, the <q>Essential</q> exception applies. For example, in digital maps, the position of pins is analogous to the position of places shown on the map. If there are many pins close together, the spacing between pins and neighboring pins will often be below 24 CSS pixels. It is essential to show the pins at the correct map location, therefore the Essential exception applies. A similar example is an interactive data visualization where targets are necessarily dense. Another example is where jurisdictions legally require online forms to replicate paper forms, which can impose constraints on the size of targets. In such jurisdictions, any legal requirement to replicate small targets can be considered essential. When the "Essential" exception is applicable, authors are strongly encouraged to provide equivalent functionality through alternative means to the extent practical.</li>
             </ul>
         </section>