Index: wp-content/themes/twentytwelve/style.css
===================================================================
--- wp-content/themes/twentytwelve/style.css	(revision 21440)
+++ wp-content/themes/twentytwelve/style.css	(working copy)
@@ -835,7 +835,9 @@
 .entry-content abbr,
 .comment-content abbr,
 .entry-content dfn,
-.comment-content dfn {
+.comment-content dfn,
+.entry-content acronym,
+.comment-content acronym {
 	border-bottom: 1px dotted #666;
 	cursor: help;
 }