Index: src/wp-admin/includes/class-wp-press-this.php
===================================================================
--- src/wp-admin/includes/class-wp-press-this.php	(revision 31632)
+++ src/wp-admin/includes/class-wp-press-this.php	(working copy)
@@ -353,7 +353,7 @@
 		if ( ! is_string( $url ) ) {
 			return '';
 		}
-		
+
 		$url = $this->_limit_string( $url );
 
 		// HTTP 1.1 allows 8000 chars but the "de-facto" standard supported in all current browsers is 2048.
@@ -470,7 +470,7 @@
 					break;
 			}
 		}
-		
+
 		return $data;
 	}
 
@@ -821,11 +821,11 @@
 				<div class="ajaxtag hide-if-no-js">
 					<label class="screen-reader-text" for="new-tag-post_tag"><?php _e( 'Tags' ); ?></label>
 					<p>
-						<input type="text" id="new-tag-post_tag" name="newtag[post_tag]" class="newtag form-input-tip" size="16" autocomplete="off" value="" />
+						<input type="text" id="new-tag-post_tag" name="newtag[post_tag]" class="newtag form-input-tip" size="16" autocomplete="off" value="" aria-describedby="new-tag-desc" />
 						<button type="button" class="button tagadd"><?php _e( 'Add' ); ?></button>
 					</p>
 				</div>
-				<p class="howto">
+				<p class="howto" id="new-tag-desc">
 					<?php echo $taxonomy->labels->separate_items_with_commas; ?>
 				</p>
 			<?php } ?>
Index: src/wp-admin/includes/meta-boxes.php
===================================================================
--- src/wp-admin/includes/meta-boxes.php	(revision 31632)
+++ src/wp-admin/includes/meta-boxes.php	(working copy)
@@ -418,10 +418,10 @@
  	<?php if ( $user_can_assign_terms ) : ?>
 	<div class="ajaxtag hide-if-no-js">
 		<label class="screen-reader-text" for="new-tag-<?php echo $tax_name; ?>"><?php echo $box['title']; ?></label>
-		<p><input type="text" id="new-tag-<?php echo $tax_name; ?>" name="newtag[<?php echo $tax_name; ?>]" class="newtag form-input-tip" size="16" autocomplete="off" value="" />
+		<p><input type="text" id="new-tag-<?php echo $tax_name; ?>" name="newtag[<?php echo $tax_name; ?>]" class="newtag form-input-tip" size="16" autocomplete="off" value="" aria-describedby="new-tag-desc" />
 		<input type="button" class="button tagadd" value="<?php esc_attr_e('Add'); ?>" /></p>
 	</div>
-	<p class="howto"><?php echo $taxonomy->labels->separate_items_with_commas; ?></p>
+	<p class="howto" id="new-tag-desc"><?php echo $taxonomy->labels->separate_items_with_commas; ?></p>
 	<?php endif; ?>
 	</div>
 	<div class="tagchecklist"></div>