[css-multicol-1] Adds Accessibility Considerations

Fixes: w3c#6283

css-multicol-1/Overview.bs

@@ -385,7 +385,8 @@ The Multi-Column Model</h2>
 	Future specifications may add additional functionality. 
 	For example, columns of different widths and different backgrounds may be supported.
 
-	Note: Multicol containers with column heights larger than the viewport may pose accessibility issues.
+	Note: Multicol containers with column heights larger than the viewport may pose accessibility issues. 
+	See <a href="#a11y">Accessibility Considerations</a> for more details.
 
 
 <h2 id="the-number-and-width-of-columns">
@@ -1539,6 +1540,12 @@ Pagination and Overflow Outside Multicol Containers</h3>
 
 This appendix is <em>informative</em>.
 
+<h3 id="changes-from-20210212">Changes from the <a href="https://www.w3.org/TR/2021/WD-css-multicol-1-20210212/">Working Draft (WD) of 12 February 2021</a></h3>
+
+<ul>
+    <li>Adds an accessibility considerations section. <a href="https://github.com/w3c/csswg-drafts/issues/6283">Request from APA after review.</a></li>
+</ul>
+
 <h3 id="changes-from-20191015">Changes from the <a href="https://www.w3.org/TR/2019/WD-css-multicol-1-20191015/">Working Draft (WD) of 15 October 2019</a></h3>
 
 <ul>
@@ -1616,6 +1623,12 @@ This appendix is <em>informative</em>.
 Multicol introduces no new privacy leaks,
 or security considerations beyond "implement it correctly".
 
+<h2 class="no-num" id="a11y">Accessibility Considerations</h2>
+
+Setting container height and line length can pose challenges for people with visual or cognitive disabilities. 
+See <a href="https://www.w3.org/WAI/WCAG21/Understanding/reflow.html">WCAG Success Criterion 1.4.10 Reflow</a> and
+<a href="https://www.w3.org/WAI/WCAG21/quickref/#visual-presentation">WCAG 1.4.8 Visual Presentation</a> to understand user needs.
+
 <h2 class=no-num id=acknowledgments>
 Acknowledgments</h2>