diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index ce5e2259..139e2cef 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -329,6 +329,10 @@
     "message": "Support",
     "description": "Label for the external link to style's support site"
   },
+  "externalUsercssDocument": {
+    "message": "Documentation for Usercss",
+    "description": "Label for the external link to usercss documentation"
+  },
   "filteredStyles": {
     "message": "$numShown$ shown of $numTotal$ total",
     "description": "TL note - make this message short",
diff --git a/edit/edit.css b/edit/edit.css
index 0f63120c..660b8c7b 100644
--- a/edit/edit.css
+++ b/edit/edit.css
@@ -134,6 +134,10 @@ h2 .svg-icon, label .svg-icon {
 #options .option > * {
   padding-right: 0.25rem;
 }
+/* footer */
+#footer {
+  margin-top: 1em;
+}
 /************ content ***********/
 #sections > div {
   margin: 0.7rem;
diff --git a/edit/source-editor.js b/edit/source-editor.js
index 846f6e1e..42bfb0c6 100644
--- a/edit/source-editor.js
+++ b/edit/source-editor.js
@@ -17,6 +17,11 @@ function createSourceEditor(style) {
     ]})
   );
 
+  $('#header').appendChild($element({
+    id: 'footer',
+    appendChild: makeLink('https://github.com/openstyles/stylus/wiki/Usercss', t('externalUsercssDocument'))
+  }));
+
   setupOptionsExpand();
 
   // dirty reporter