diff --git a/xpfe/browser/samples/dexanimdialog.xul b/xpfe/browser/samples/dexanimdialog.xul
index f5e6e22c908c..e3c1a27e3d30 100644
--- a/xpfe/browser/samples/dexanimdialog.xul
+++ b/xpfe/browser/samples/dexanimdialog.xul
@@ -1,7 +1,9 @@
 <?xml version="1.0"?>
 <?xml-stylesheet href="xul.css" type="text/css"?> 
 <!DOCTYPE window>
-<!-- dialog containing a control requiring initial setup -->
+<!-- DO NOT LOCALIZE: this file is source documentation; not part of the build -->
+<!-- dialog containing a control requiring initial setup, including some
+     JavaScript-testing animations -->
 <xul:window
     xmlns:html="http://www.w3.org/TR/REC-html40"
     xmlns:xul ="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
diff --git a/xpfe/browser/samples/dexanimmaster.xul b/xpfe/browser/samples/dexanimmaster.xul
index 2598db163390..6828aba5e98d 100644
--- a/xpfe/browser/samples/dexanimmaster.xul
+++ b/xpfe/browser/samples/dexanimmaster.xul
@@ -1,6 +1,7 @@
 <?xml version="1.0"?>
 <?xml-stylesheet href="xul.css" type="text/css"?>
 <!DOCTYPE window>
+<!-- DO NOT LOCALIZE: this file is source documentation; not part of the build -->
 <!-- sample interface for bringing up a nonmodal dialog, including some
      JavaScript-testing animations -->
 <window
diff --git a/xpfe/browser/samples/dexparamdialog.xul b/xpfe/browser/samples/dexparamdialog.xul
index 97dc03a01aa8..75eca1be1378 100644
--- a/xpfe/browser/samples/dexparamdialog.xul
+++ b/xpfe/browser/samples/dexparamdialog.xul
@@ -1,7 +1,9 @@
 <?xml version="1.0"?>
 <?xml-stylesheet href="xul.css" type="text/css"?> 
 <!DOCTYPE window>
-<!-- dialog containing a control requiring initial setup -->
+<!-- DO NOT LOCALIZE: this file is source documentation; not part of the build -->
+<!-- dialog containing a control requiring initial setup, expecting
+     initial settings to be passed in as parameters -->
 <xul:window
     xmlns:html="http://www.w3.org/TR/REC-html40"
     xmlns:xul ="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
diff --git a/xpfe/browser/samples/dexparammaster.xul b/xpfe/browser/samples/dexparammaster.xul
index 3e5ae2ce81a4..b122822d62ba 100644
--- a/xpfe/browser/samples/dexparammaster.xul
+++ b/xpfe/browser/samples/dexparammaster.xul
@@ -1,7 +1,8 @@
 <?xml version="1.0"?>
 <?xml-stylesheet href="xul.css" type="text/css"?>
 <!DOCTYPE window>
-<!-- Simple sample interface for bringing up a nonmodal dialog -->
+<!-- DO NOT LOCALIZE: this file is source documentation; not part of the build -->
+<!-- Sample interface for bringing up and passing parameters to a dialog -->
 <xul:window
     xmlns:html="http://www.w3.org/TR/REC-html40"
     xmlns:xul ="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
diff --git a/xpfe/browser/samples/dexsimpledialog.xul b/xpfe/browser/samples/dexsimpledialog.xul
index dd49d3947b91..07fe737040c1 100644
--- a/xpfe/browser/samples/dexsimpledialog.xul
+++ b/xpfe/browser/samples/dexsimpledialog.xul
@@ -1,6 +1,7 @@
 <?xml version="1.0"?>
 <?xml-stylesheet href="xul.css" type="text/css"?> 
 <!DOCTYPE window>
+<!-- DO NOT LOCALIZE: this file is source documentation; not part of the build -->
 <!-- dialog containing a control requiring initial setup -->
 <xul:window
     xmlns:html="http://www.w3.org/TR/REC-html40"
diff --git a/xpfe/browser/samples/dexsimplemaster.xul b/xpfe/browser/samples/dexsimplemaster.xul
index 131d1db1ac82..352c00227964 100644
--- a/xpfe/browser/samples/dexsimplemaster.xul
+++ b/xpfe/browser/samples/dexsimplemaster.xul
@@ -1,7 +1,8 @@
 <?xml version="1.0"?>
 <?xml-stylesheet href="xul.css" type="text/css"?>
 <!DOCTYPE window>
-<!-- Simple sample interface for bringing up a nonmodal dialog -->
+<!-- DO NOT LOCALIZE: this file is source documentation; not part of the build -->
+<!-- Simple sample interface for bringing up a dialog -->
 <xul:window
     xmlns:html="http://www.w3.org/TR/REC-html40"
     xmlns:xul ="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"