diff --git a/wicket-core/src/test/java/org/apache/wicket/core/request/mapper/BasicResourceReferenceMapperTest.java b/wicket-core/src/test/java/org/apache/wicket/core/request/mapper/BasicResourceReferenceMapperTest.java
index def27a40688..d6dd3e5fbc8 100644
--- a/wicket-core/src/test/java/org/apache/wicket/core/request/mapper/BasicResourceReferenceMapperTest.java
+++ b/wicket-core/src/test/java/org/apache/wicket/core/request/mapper/BasicResourceReferenceMapperTest.java
@@ -83,7 +83,7 @@ void decode1()
 	@Test
 	void decode1A()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference1?en");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference1?2~ennullnull");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		// assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class); // TODO use hamcrest or assertj
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -120,7 +120,7 @@ void decode2()
 	@Test
 	void decode2A()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference1?-style&p1=v1&p2=v2");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference1?null5~stylenull&p1=v1&p2=v2");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -139,7 +139,7 @@ void decode2A()
 	@Test
 	void decode3()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference2/name2?en_EN");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference2/name2?5~en_ENnullnull");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
@@ -158,7 +158,7 @@ void decode3()
 	@Test
 	void decode3A()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference2/name2?en_EN-style");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference2/name2?5~en_EN5~stylenull");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -188,7 +188,7 @@ void decode3B()
 	void decode4()
 	{
 		Url url = Url
-			.parse("wicket/resource/" + CLASS_NAME + "/reference2/name2?en_EN&p1=v1&p2=v2");
+			.parse("wicket/resource/" + CLASS_NAME + "/reference2/name2?5~en_ENnullnull&p1=v1&p2=v2");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -206,7 +206,7 @@ void decode4()
 	@Test
 	void decode5()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference3?-style");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference3?null5~stylenull");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -224,7 +224,7 @@ void decode5()
 	@Test
 	void decode6()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference3?-style&p1=v1&p2=v2");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference3?null5~stylenull&p1=v1&p2=v2");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -244,7 +244,7 @@ void decode6()
 	@Test
 	void decode7()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference4?en-style");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference4?2~en5~stylenull");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -262,7 +262,7 @@ void decode7()
 	@Test
 	void decode7A()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference4?sk");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference4?2~sknullnull");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertNull(handler);
 	}
@@ -273,7 +273,7 @@ void decode7A()
 	@Test
 	void decode8()
 	{
-		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference4?en-style&p1=v1&p2=v2");
+		Url url = Url.parse("wicket/resource/" + CLASS_NAME + "/reference4?2~en5~stylenull&p1=v1&p2=v2");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -293,7 +293,7 @@ void decode8()
 	void decode9()
 	{
 		Url url = Url.parse("wicket/resource/" + CLASS_NAME
-			+ "/reference5?en--variation&p1=v1&p2=v2");
+			+ "/reference5?2~ennull9~variation&p1=v1&p2=v2");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -313,7 +313,7 @@ void decode9()
 	void decode10()
 	{
 		Url url = Url.parse("wicket/resource/" + CLASS_NAME
-			+ "/reference6?en-style-variation&p1=v1&p2=v2");
+			+ "/reference6?2~en5~style9~variation&p1=v1&p2=v2");
 		IRequestHandler handler = encoder.mapRequest(getRequest(url));
 		assertThat(handler).isInstanceOf(ResourceReferenceRequestHandler.class);
 		ResourceReferenceRequestHandler h = (ResourceReferenceRequestHandler)handler;
@@ -375,7 +375,7 @@ void encode3()
 		ResourceReferenceRequestHandler handler = new ResourceReferenceRequestHandler(reference2,
 			null);
 		Url url = encoder.mapHandler(handler);
-		assertEquals("wicket/resource/" + CLASS_NAME + "/reference2/name2?en_EN", url.toString());
+		assertEquals("wicket/resource/" + CLASS_NAME + "/reference2/name2?5~en_ENnullnull", url.toString());
 	}
 
 	/**
@@ -392,7 +392,7 @@ void encode4()
 			parameters);
 
 		Url url = encoder.mapHandler(handler);
-		assertEquals("wicket/resource/" + CLASS_NAME + "/reference2/name2?en_EN&p1=v1&p2=v2",
+		assertEquals("wicket/resource/" + CLASS_NAME + "/reference2/name2?5~en_ENnullnull&p1=v1&p2=v2",
 			url.toString());
 	}
 
@@ -405,7 +405,7 @@ void encode5()
 		ResourceReferenceRequestHandler handler = new ResourceReferenceRequestHandler(reference3,
 			null);
 		Url url = encoder.mapHandler(handler);
-		assertEquals("wicket/resource/" + CLASS_NAME + "/reference3?-style", url.toString());
+		assertEquals("wicket/resource/" + CLASS_NAME + "/reference3?null5~stylenull", url.toString());
 	}
 
 	/**
@@ -422,7 +422,7 @@ void encode6()
 			parameters);
 
 		Url url = encoder.mapHandler(handler);
-		assertEquals("wicket/resource/" + CLASS_NAME + "/reference3?-style&p1=v1&p2=v2",
+		assertEquals("wicket/resource/" + CLASS_NAME + "/reference3?null5~stylenull&p1=v1&p2=v2",
 			url.toString());
 	}
 
@@ -435,7 +435,7 @@ void encode7()
 		ResourceReferenceRequestHandler handler = new ResourceReferenceRequestHandler(reference4,
 			null);
 		Url url = encoder.mapHandler(handler);
-		assertEquals("wicket/resource/" + CLASS_NAME + "/reference4?en-style", url.toString());
+		assertEquals("wicket/resource/" + CLASS_NAME + "/reference4?2~en5~stylenull", url.toString());
 	}
 
 	/**
@@ -452,7 +452,7 @@ void encode8()
 			parameters);
 
 		Url url = encoder.mapHandler(handler);
-		assertEquals("wicket/resource/" + CLASS_NAME + "/reference4?en-style&p1=v1&p2=v2",
+		assertEquals("wicket/resource/" + CLASS_NAME + "/reference4?2~en5~stylenull&p1=v1&p2=v2",
 			url.toString());
 	}
 
@@ -466,7 +466,7 @@ void encode9()
 			null);
 
 		Url url = encoder.mapHandler(handler);
-		assertEquals("wicket/resource/" + CLASS_NAME + "/reference5?en--variation", url.toString());
+		assertEquals("wicket/resource/" + CLASS_NAME + "/reference5?2~ennull9~variation", url.toString());
 	}
 
 	/**
diff --git a/wicket-core/src/test/java/org/apache/wicket/markup/html/form/imagebutton/ImageButtonTest.java b/wicket-core/src/test/java/org/apache/wicket/markup/html/form/imagebutton/ImageButtonTest.java
index 7e7ffae0304..5403b627119 100644
--- a/wicket-core/src/test/java/org/apache/wicket/markup/html/form/imagebutton/ImageButtonTest.java
+++ b/wicket-core/src/test/java/org/apache/wicket/markup/html/form/imagebutton/ImageButtonTest.java
@@ -38,19 +38,19 @@ void imageButton() throws Exception
 		tester.startPage(Home.class);
 
 		tester.clickLink("goCanadian");
-		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?en_CA\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?5~en_CAnullnull\"");
 
 		tester.clickLink("goChinese");
-		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?zh_CN\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?5~zh_CNnullnull\"");
 
 		tester.clickLink("goDanish");
-		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?da_DK\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?5~da_DKnullnull\"");
 
 		tester.clickLink("goDutch");
-		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?nl_NL\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?5~nl_NLnullnull\"");
 
 		tester.clickLink("goGerman");
-		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?de_DE\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\\?5~de_DEnullnull\"");
 
 		tester.clickLink("goUS");
 		tester.assertContains("resource/org.apache.wicket.markup.html.form.imagebutton.Home/Beer.gif\"");
diff --git a/wicket-core/src/test/java/org/apache/wicket/markup/html/image/ImageTest.java b/wicket-core/src/test/java/org/apache/wicket/markup/html/image/ImageTest.java
index 04e8ad94e6b..9b87d7eca4d 100644
--- a/wicket-core/src/test/java/org/apache/wicket/markup/html/image/ImageTest.java
+++ b/wicket-core/src/test/java/org/apache/wicket/markup/html/image/ImageTest.java
@@ -38,19 +38,19 @@ void test_1() throws Exception
 		tester.startPage(Home.class);
 
 		tester.clickLink("goCanadian");
-		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?en_CA\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?5~en_CAnullnull\"");
 
 		tester.clickLink("goChinese");
-		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?zh_CN\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?5~zh_CNnullnull\"");
 
 		tester.clickLink("goDanish");
-		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?da_DK\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?5~da_DKnullnull\"");
 
 		tester.clickLink("goDutch");
-		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?nl_NL\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?5~nl_NLnullnull\"");
 
 		tester.clickLink("goGerman");
-		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?de_DE\"");
+		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\\?5~de_DEnullnull\"");
 
 		tester.clickLink("goUS");
 		tester.assertContains("resource/org.apache.wicket.markup.html.image.Home/Beer.gif\"");
diff --git a/wicket-core/src/test/java/org/apache/wicket/markup/html/link/AutolinkPageExpectedResult_1.html b/wicket-core/src/test/java/org/apache/wicket/markup/html/link/AutolinkPageExpectedResult_1.html
index fcf1cade818..4e00ff16e50 100644
--- a/wicket-core/src/test/java/org/apache/wicket/markup/html/link/AutolinkPageExpectedResult_1.html
+++ b/wicket-core/src/test/java/org/apache/wicket/markup/html/link/AutolinkPageExpectedResult_1.html
@@ -25,9 +25,9 @@
 <wicket:link autolink="true">
 <a href="./org.apache.wicket.markup.html.link.subdir.Page1">Home</a>
 <link href="../resource/org.apache.wicket.markup.html.link.AutolinkPage_1/test.css"/>
-<link href="../resource/org.apache.wicket.markup.html.link.AutolinkPage_1/test2.css?-myStyle"/>
-<link href="../resource/org.apache.wicket.markup.html.link.AutolinkPage_1/test3.css?de_DE"/>
-<link href="../resource/org.apache.wicket.markup.html.link.AutolinkPage_1/$up$/$up$/html/link/test2.css?-myStyle"/>
+<link href="../resource/org.apache.wicket.markup.html.link.AutolinkPage_1/test2.css?null7~myStylenull"/>
+<link href="../resource/org.apache.wicket.markup.html.link.AutolinkPage_1/test3.css?5~de_DEnullnull"/>
+<link href="../resource/org.apache.wicket.markup.html.link.AutolinkPage_1/$up$/$up$/html/link/test2.css?null7~myStylenull"/>
 <a href="/root/test.html">Home</a>
 <a href="./org.apache.wicket.markup.html.link.Page1">Home</a>
   <a href="http://www.google.com">Google</a>
diff --git a/wicket-core/src/test/java/org/apache/wicket/resource/ResourceUtilTest.java b/wicket-core/src/test/java/org/apache/wicket/resource/ResourceUtilTest.java
index 5d1c39ab024..7a4fe9f74fd 100644
--- a/wicket-core/src/test/java/org/apache/wicket/resource/ResourceUtilTest.java
+++ b/wicket-core/src/test/java/org/apache/wicket/resource/ResourceUtilTest.java
@@ -32,30 +32,30 @@ class ResourceUtilTest
 	@Test
 	void decodeResourceReferenceAttributesWithString() throws Exception
 	{
-		String urlParameter = "en_GB-style-variation";		
+		String urlParameter = "5~en_GB5~style9~variation";		
 		UrlAttributes attributes = ResourceUtil.decodeResourceReferenceAttributes(urlParameter);
 		
 		assertEquals(Locale.UK, attributes.getLocale());
 		assertEquals("style", attributes.getStyle());
 		assertEquals("variation", attributes.getVariation());
 		
-		attributes = ResourceUtil.decodeResourceReferenceAttributes("it_IT");
+		attributes = ResourceUtil.decodeResourceReferenceAttributes("5~it_ITnullnull");
 		
 		assertEquals(Locale.ITALY, attributes.getLocale());
 		assertNull(attributes.getStyle());
 		assertNull(attributes.getVariation());
 		
-		attributes = ResourceUtil.decodeResourceReferenceAttributes("-style-variation");
+		attributes = ResourceUtil.decodeResourceReferenceAttributes("null5~style9~variation");
 		assertNull(attributes.getLocale());
 		assertEquals("style", attributes.getStyle());
 		assertEquals("variation", attributes.getVariation());
 
-		attributes = ResourceUtil.decodeResourceReferenceAttributes("--variation");
+		attributes = ResourceUtil.decodeResourceReferenceAttributes("nullnull9~variation");
 		assertNull(attributes.getLocale());
 		assertNull(attributes.getStyle());
 		assertEquals("variation", attributes.getVariation());
 
-		attributes = ResourceUtil.decodeResourceReferenceAttributes("-style");
+		attributes = ResourceUtil.decodeResourceReferenceAttributes("null5~stylenull");
 		assertNull(attributes.getLocale());
 		assertEquals("style", attributes.getStyle());
 		assertNull(attributes.getVariation());
@@ -69,13 +69,13 @@ void decodeResourceReferenceAttributesWithUrl() throws Exception
 
 		assertEquals(new UrlAttributes(null, null, null), attributes);
 
-		url = Url.parse("www.funny.url/?de_DE");
+		url = Url.parse("www.funny.url/?5~de_DEnullnull");
 		attributes = ResourceUtil.decodeResourceReferenceAttributes(url);
 		assertEquals(Locale.GERMANY, attributes.getLocale());
 		assertNull(attributes.getStyle());
 		assertNull(attributes.getVariation());
 
-		url = Url.parse("www.funny.url/?-style");
+		url = Url.parse("www.funny.url/?null5~stylenull");
 		attributes = ResourceUtil.decodeResourceReferenceAttributes(url);
 		assertNull(attributes.getLocale());
 		assertEquals("style", attributes.getStyle());
@@ -90,11 +90,11 @@ void encodeResourceReferenceAttributes() throws Exception
 
 		attributes = new UrlAttributes(Locale.CANADA_FRENCH, "style", "variation");
 		
-		assertEquals("fr_CA-style-variation", ResourceUtil.encodeResourceReferenceAttributes(attributes));
+		assertEquals("5~fr_CA5~style9~variation", ResourceUtil.encodeResourceReferenceAttributes(attributes));
 		
 		attributes = new UrlAttributes(null, null, "variation");
 		
-		assertEquals("--variation", ResourceUtil.encodeResourceReferenceAttributes(attributes));
+		assertEquals("nullnull9~variation", ResourceUtil.encodeResourceReferenceAttributes(attributes));
 	}
 
 	@Test
@@ -136,7 +136,7 @@ void encodeResourceReferenceAttributesWithResource() throws Exception
 		Mockito.when(resourceReference.getUrlAttributes()).thenReturn(attributes);
 		ResourceUtil.encodeResourceReferenceAttributes(url, resourceReference);
 		
-		assertEquals(urlString + "?fr_CA-style-variation", url.toString());
+		assertEquals(urlString + "?5~fr_CA5~style9~variation", url.toString());
 		
 		Mockito.reset(resourceReference);
 		
@@ -147,6 +147,6 @@ void encodeResourceReferenceAttributesWithResource() throws Exception
 		Mockito.when(resourceReference.getUrlAttributes()).thenReturn(attributes);
 		ResourceUtil.encodeResourceReferenceAttributes(url, resourceReference);
 		
-		assertEquals(urlString + "?--variation", url.toString());
+		assertEquals(urlString + "?nullnull9~variation", url.toString());
 	}
 }