diff --git a/htmlcssguide.html b/htmlcssguide.html
index 7421739..7b6074c 100644
--- a/htmlcssguide.html
+++ b/htmlcssguide.html
@@ -420,7 +420,8 @@ instead of an error.)</p>
 wrapping long lines if it significantly improves readability.</p>
 
 <p>When line-wrapping, each continuation line should be indented at least 4
-additional spaces from the original line.</p>
+additional spaces from the original line to distinguish wrapped attributes from
+child elements.</p>
 
 <pre><code class="language-html good">&lt;md-progress-circular md-mode="indeterminate" class="md-accent"
     ng-show="ctrl.loading" md-diameter="35"&gt;