@@ -1,6 +1,6 @@
 
 const loadCopyButton = () => {
-    /* Add a [>>>] button on the top-right corner of code samples to hide
+    /* Add a [>>>] button in the top-right corner of code samples to hide
      * the >>> and ... prompts and the output and thus make the code
      * copyable. */
     const hide_text = 'Hide the prompts and output'
@@ -19,6 +19,8 @@ const loadCopyButton = () => {
         if (buttonEl.dataset.hidden === 'false') {
             // hide the code output
             codeEl.querySelectorAll('.go, .gp, .gt').forEach(el => el.hidden = true)
+            // tracebacks (.gt) contain bare text elements that need to be
+            // wrapped in a span to hide or show the element
             codeEl.querySelectorAll('.gt').forEach(el => {
                 while ((el = el.nextSibling) && el.nodeType !== Node.DOCUMENT_NODE) {
                     if (el.nodeType === Node.ELEMENT_NODE && el.matches(".gp, .go")) {