diff --git a/htroot/CacheResource_p.java b/htroot/CacheResource_p.java
index ac151bdf1..d4b189677 100644
--- a/htroot/CacheResource_p.java
+++ b/htroot/CacheResource_p.java
@@ -32,6 +32,7 @@ import java.nio.charset.StandardCharsets;
 import net.yacy.cora.document.id.DigestURL;
 import net.yacy.cora.federate.yacy.CacheStrategy;
 import net.yacy.cora.protocol.ClientIdentification;
+import net.yacy.cora.protocol.HeaderFramework;
 import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.cora.protocol.ResponseHeader;
 import net.yacy.cora.util.ConcurrentLog;
@@ -77,7 +78,7 @@ public class CacheResource_p {
         }
 
         // check request type
-        if (header.get("EXT", "html").equals("png")) {
+        if (header.get(HeaderFramework.CONNECTION_PROP_EXT, "html").equals("png")) {
             // a png was requested
             return ImageParser.parse(u, resource);
         }
diff --git a/htroot/Tables_p.java b/htroot/Tables_p.java
index 50738e5fc..eaf2f5af1 100644
--- a/htroot/Tables_p.java
+++ b/htroot/Tables_p.java
@@ -26,6 +26,7 @@ import java.util.Map;
 import java.util.regex.Pattern;
 
 import net.yacy.cora.document.encoding.UTF8;
+import net.yacy.cora.protocol.HeaderFramework;
 import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.cora.util.ConcurrentLog;
 import net.yacy.cora.util.SpaceExceededException;
@@ -40,7 +41,7 @@ public class Tables_p {
         final Switchboard sb = (Switchboard) env;
         final serverObjects prop = new serverObjects();
 
-        final String ext = header.get("EXT", "");
+        final String ext = header.get(HeaderFramework.CONNECTION_PROP_EXT, "");
         //final boolean json = ext.equals("json");
         final boolean xml = ext.equals("xml");
         
diff --git a/htroot/ViewFavicon.java b/htroot/ViewFavicon.java
index 53984c7ea..2ca914782 100644
--- a/htroot/ViewFavicon.java
+++ b/htroot/ViewFavicon.java
@@ -86,7 +86,7 @@ public class ViewFavicon {
 	public static Object respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
 
 		final Switchboard sb = (Switchboard) env;
-		String ext = header.get("EXT", null);
+		String ext = header.get(HeaderFramework.CONNECTION_PROP_EXT, null);
 		boolean isPNGTarget = "png".equalsIgnoreCase(ext);
 
 		ImageInputStream imageInStream = null;
diff --git a/htroot/ViewImage.java b/htroot/ViewImage.java
index 4625e9367..bc1792a92 100644
--- a/htroot/ViewImage.java
+++ b/htroot/ViewImage.java
@@ -76,7 +76,7 @@ public class ViewImage {
 			throw new TemplateMissingParameterException("please fill at least url or code parameter");
 		}
 
-		String ext = header.get("EXT", null);
+		String ext = header.get(HeaderFramework.CONNECTION_PROP_EXT, null);
 		final boolean auth = Domains.isLocalhost(header.get(HeaderFramework.CONNECTION_PROP_CLIENTIP, ""))
 				|| sb.verifyAuthentication(header); // handle access rights
 
diff --git a/htroot/api/linkstructure.java b/htroot/api/linkstructure.java
index af1f4712e..ad27c15aa 100644
--- a/htroot/api/linkstructure.java
+++ b/htroot/api/linkstructure.java
@@ -41,7 +41,7 @@ public class linkstructure {
     public static serverObjects respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
         final servletProperties prop = new servletProperties();
         
-        final String ext = header.get("EXT", "");
+        final String ext = header.get(HeaderFramework.CONNECTION_PROP_EXT, "");
         //final boolean json = ext.equals("json");
         final boolean xml = ext.equals("xml");
         
diff --git a/htroot/api/snapshot.java b/htroot/api/snapshot.java
index 86fc23602..5c4ebcd78 100644
--- a/htroot/api/snapshot.java
+++ b/htroot/api/snapshot.java
@@ -38,6 +38,7 @@ import net.yacy.cora.document.encoding.UTF8;
 import net.yacy.cora.document.feed.RSSFeed;
 import net.yacy.cora.document.feed.RSSMessage;
 import net.yacy.cora.document.id.DigestURL;
+import net.yacy.cora.protocol.HeaderFramework;
 import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.cora.util.ConcurrentLog;
 import net.yacy.cora.util.Html2Image;
@@ -67,7 +68,7 @@ public class snapshot {
         final Switchboard sb = (Switchboard) env;
 
         final boolean authenticated = sb.adminAuthenticated(header) >= 2;
-        final String ext = header.get("EXT", "");
+        final String ext = header.get(HeaderFramework.CONNECTION_PROP_EXT, "");
         
         
         if (ext.equals("rss")) {
diff --git a/htroot/api/table_p.java b/htroot/api/table_p.java
index 46dff501b..65100f25a 100644
--- a/htroot/api/table_p.java
+++ b/htroot/api/table_p.java
@@ -25,6 +25,7 @@ import java.util.Map;
 import java.util.regex.Pattern;
 
 import net.yacy.cora.document.encoding.UTF8;
+import net.yacy.cora.protocol.HeaderFramework;
 import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.cora.util.CommonPattern;
 import net.yacy.cora.util.ConcurrentLog;
@@ -40,7 +41,7 @@ public class table_p {
         final Switchboard sb = (Switchboard) env;
         final serverObjects prop = new serverObjects();
 
-        final String EXT = header.get("EXT", "");
+        final String EXT = header.get(HeaderFramework.CONNECTION_PROP_EXT, "");
         final boolean html = EXT.equals("html");
         final boolean xml = EXT.equals("xml");
 
diff --git a/htroot/osm.java b/htroot/osm.java
index 47d86e587..09828d3bb 100644
--- a/htroot/osm.java
+++ b/htroot/osm.java
@@ -18,6 +18,7 @@
  *  If not, see <http://www.gnu.org/licenses/>.
  */
 
+import net.yacy.cora.protocol.HeaderFramework;
 import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.peers.graphics.EncodedImage;
 import net.yacy.peers.graphics.OSMTile;
@@ -58,7 +59,7 @@ public class osm {
          * The (C) symbol is not available in our font, so we use the letters (C) instead.
          */
         PrintTool.print(map, map.getWidth() - 6, map.getHeight() - 6, 0, "(C) OPENSTREETMAP CONTRIBUTORS", 1, 80);
-        return new EncodedImage(map, header.get("EXT", null), true);
+        return new EncodedImage(map, header.get(HeaderFramework.CONNECTION_PROP_EXT, null), true);
    }
 
 }
\ No newline at end of file
diff --git a/htroot/suggest.java b/htroot/suggest.java
index 552b0e601..e8867c05a 100644
--- a/htroot/suggest.java
+++ b/htroot/suggest.java
@@ -56,7 +56,7 @@ public class suggest {
         final Switchboard sb = (Switchboard) env;
         final servletProperties prop = new servletProperties();
 
-        final String ext = header.get("EXT", "");
+        final String ext = header.get(HeaderFramework.CONNECTION_PROP_EXT, "");
         final boolean json = ext.equals("json");
         final boolean xml = ext.equals("xml");
         
diff --git a/htroot/yacy/seedlist.java b/htroot/yacy/seedlist.java
index dba529837..af93b5ba0 100644
--- a/htroot/yacy/seedlist.java
+++ b/htroot/yacy/seedlist.java
@@ -23,6 +23,7 @@ import java.util.ArrayList;
 import java.util.Map;
 import java.util.Set;
 
+import net.yacy.cora.protocol.HeaderFramework;
 import net.yacy.cora.protocol.RequestHeader;
 import net.yacy.cora.util.JSONObject;
 import net.yacy.peers.Seed;
@@ -71,7 +72,7 @@ public final class seedlist {
         final serverObjects prop = new serverObjects();
         
         // write simple-encoded seed lines or json
-        String EXT = header.get("EXT");
+        String EXT = header.get(HeaderFramework.CONNECTION_PROP_EXT);
         boolean json = EXT != null && EXT.equals("json");
         boolean xml = EXT != null && EXT.equals("xml");