diff -u b/core/modules/system/css/system.theme.css b/core/modules/system/css/system.theme.css
--- b/core/modules/system/css/system.theme.css
+++ b/core/modules/system/css/system.theme.css
@@ -530,7 +530,7 @@
   margin-top: 0.769em;
 }
 
-/* See .color-success in Seven's colors.css */
+/* @see .color-success in Seven's colors.css */
 .messages--status {
   color: #325e1c;
   background-color: #f3faef;
@@ -544,7 +544,7 @@
   margin-left: 0;
 }
 
-/* See .color-warning in Seven's colors.css */
+/* @see .color-warning in Seven's colors.css */
 .messages--warning {
   background-color: #fdf8ed;
   background-image: url(../../../misc/icons/e29700/warning.svg);
@@ -557,7 +557,7 @@
   box-shadow: 8px 0 0 #e09600;
 }
 
-/* See .color-error in Seven's colors.css */
+/* @see .color-error in Seven's colors.css */
 .messages--error {
   background-color: #fcf4f2;
   color: #a51b00;
diff -u b/core/themes/seven/css/components/tables.css b/core/themes/seven/css/components/tables.css
--- b/core/themes/seven/css/components/tables.css
+++ b/core/themes/seven/css/components/tables.css
@@ -38,7 +38,7 @@
   background: #f7fcff;
 }
 
-/* See colors.css */
+/* @see colors.css */
 tbody tr.color-warning:hover,
 tbody tr.color-warning:focus {
   background: #fdf8ed;