clarifying name, role, value (#2207)

closes #2142

In an attempt to add clarity that it's not just that a name, role and
value are exposed but the **correct** name role and value are exposed, I
have simply added the word "accurate" to two sentences. This will help
imply that it's not just "information" that needs to be exposed to AT,
but "accurate information" about what the control represents.

If more modifications are necessary here, please let me know and I can
make those changes, or the editors can make changes as they see fit.

---------

Co-authored-by: Patrick H. Lauke <redux@splintered.co.uk>
Co-authored-by: Mike Gower <gowerm@ca.ibm.com>

understanding/20/name-role-value.html

@@ -23,33 +23,41 @@ <h2>Intent of Name, Role, Value</h2>
 
 
       <p>The intent of this Success Criterion is to ensure that Assistive Technologies (AT)
-         can gather information about, activate (or set) and keep up to date on the status of
+         can gather appropriate information about, activate (or set) and keep up to date on the status of
          user interface controls in the content.
       </p>
 
       <p>When standard controls from accessible technologies are used, this process is straightforward.
          If the user interface elements are used according to specification the conditions
-         of this provision will be met. (See examples  of Success Criterion 4.1.2 below)
+         of this provision will be met. (See examples of Success Criterion 4.1.2 below)
       </p>
 
       <p>If custom controls are created, however, or interface elements are programmed (in
          code or script) to have a different role and/or function than usual, then additional
-         measures need to be taken to ensure that the controls provide important information
+         measures need to be taken to ensure that the controls provide important and appropriate information
          to assistive technologies and allow themselves to be controlled by assistive technologies.
       </p>
+
+      <p>What roles and states are appropriate to convey to assistive technology will depend
+         on what the control represents. Specifics about such information are defined by other
+         specifications, such as <a href="https://www.w3.org/TR/wai-aria/">WAI-ARIA</a>, or the
+         relevant platform standards. Another factor to consider is whether there is sufficient
+         <a href="https://www.w3.org/TR/WCAG22/#dfn-accessibility-supported">accessibility support</a> 
+         with assistive technologies to convey the information as specified.
+      </p>
 
       <p>A particularly important state of a user interface control is whether or not it has
          focus. The focus state of a control can be programmatically determined, and notifications
          about change of focus are sent to user agents and assistive technology. Other examples
          of user interface control state are whether or not a checkbox or radio button has
          been selected, or whether or not a collapsible tree or list node is expanded or collapsed.
       </p>
-      
+
       <div class="note">
 
          <p>Success Criterion 4.1.2 requires a programmatically determinable name for all user
-            interface components. Names may be visible or invisible. Occasionally, the name must
-            be visible, in which case it is identified as a label. Refer to the definition of
+            interface components. Names may be visible or invisible. Occasionally, the name needs
+            to be visible, in which case it is identified as a label. Refer to the definition of
             name and label in the glossary for more information.
          </p>