[css-color-hdr] Updated privacy and accessibility considerations

Author: svgeesus

css-color-hdr/Overview.bs

@@ -866,7 +866,11 @@ Issue: Do the PQ-based color spaces require tone-mapping (OOTF) for display in d
 
 <h2 class=no-num id=privacy>Privacy Considerations</h2>
 
-No Privacy concerns have been raised on this document
+	The reason that numerical values of [=HDR headroom=]
+	are not directly exposed by the Web platform
+	is because doing so
+	would expose the current viewing conditions,
+	which would be a <a href="#headroom-privacy">privacy violation</a>.
 
 <h2 class=no-num id=security>Security Considerations</h2>
 
@@ -875,4 +879,16 @@ No Security concerns have been raised on this document
 
 <h2 class="no-num" id="a11y">Accessibility Considerations</h2>
 
-Some individuals may have a sensitivity to very bright colors, so user agents should provide a mechanism to limit the maximum luminance at user option. The toe and knee procedure in section 5.4.1 <em>Mapping to display with limited brightness range</em> of [[Rec_BT.2390]] is suggested as suitable.
+Some individuals may have a sensitivity 
+to very bright colors, 
+so user agents should provide a mechanism 
+to limit the maximum luminance at user option. 
+<span class="non-normative">The toe and knee procedure 
+	in section 5.4.1 
+	<em>Mapping to display with limited brightness range</em> 
+	of [[Rec_BT.2390]] 
+	is suggested as suitable.</span>
+
+The ''dynamic-range-limit'' property could also be set to
+''dynamic-range-limit/standard'' or ''dynamic-range-limit/constrained-high''
+in a user stylesheet.