diff --git a/htroot/yacysearch.java b/htroot/yacysearch.java
index d213d515c..f6c3ad896 100644
--- a/htroot/yacysearch.java
+++ b/htroot/yacysearch.java
@@ -533,16 +533,16 @@ public class yacysearch {
             String authorhash = null;
             if ( authori >= 0 ) {
                 // check if the author was given with single quotes or without
-                final boolean quotes = (querystring.charAt(authori + 7) == '%');
+                final boolean quotes = (querystring.charAt(authori + 7) == '(');
                 String author;
                 if ( quotes ) {
-                    int ftb = querystring.indexOf('%', authori + 8);
+                    int ftb = querystring.indexOf(')', authori + 8);
                     if ( ftb == -1 ) {
                         ftb = querystring.length() + 1;
                     }
                     author = querystring.substring(authori + 8, ftb);
-                    querystring = querystring.replace("author:%" + author + "%", "");
-                    modifier.append("author:%").append(author).append("% ");
+                    querystring = querystring.replace("author:(" + author + ")", "");
+                    modifier.append("author:(").append(author).append(") ");
                 } else {
                     int ftb = querystring.indexOf(' ', authori);
                     if ( ftb == -1 ) {
diff --git a/htroot/yacysearchtrailer.java b/htroot/yacysearchtrailer.java
index 28d735fbb..51f138c83 100644
--- a/htroot/yacysearchtrailer.java
+++ b/htroot/yacysearchtrailer.java
@@ -77,13 +77,19 @@ public class yacysearchtrailer {
             while (i < 10 && navigatorIterator.hasNext()) {
                 name = navigatorIterator.next();
                 count = namespaceNavigator.get(name);
-                nav = "inurl:" + name;
+                nav = "inurl%3A" + name;
                 queryStringForUrl = theQuery.queryStringForUrl();
                 p = queryStringForUrl.indexOf(nav);
-                prop.put("nav-namespace_element_" + i + "_on", 1);
-                prop.put(fileType, "nav-namespace_element_" + i + "_modifier", nav);
+                if (p < 0) {
+                    queryStringForUrl += "+" + nav;
+                    prop.put("nav-namespace_element_" + i + "_on", 1);
+                    prop.put(fileType, "nav-namespace_element_" + i + "_modifier", nav);
+                } else {
+                    prop.put("nav-namespace_element_" + i + "_on", 0);
+                    queryStringForUrl = (queryStringForUrl.substring(0, p) + queryStringForUrl.substring(p + nav.length())).trim();
+                }
                 prop.put(fileType, "nav-namespace_element_" + i + "_name", name);
-                prop.put(fileType, "nav-namespace_element_" + i + "_url", QueryParams.navurl(fileType.name().toLowerCase(), 0, theQuery, queryStringForUrl + "+" + nav, theQuery.urlMask.toString(), theQuery.navigators).toString());
+                prop.put(fileType, "nav-namespace_element_" + i + "_url", QueryParams.navurl(fileType.name().toLowerCase(), 0, theQuery, queryStringForUrl, theQuery.urlMask.toString(), theQuery.navigators).toString());
                 prop.put("nav-namespace_element_" + i + "_count", count);
                 prop.put("nav-namespace_element_" + i + "_nl", 1);
                 i++;
@@ -105,13 +111,20 @@ public class yacysearchtrailer {
             while (i < 20 && navigatorIterator.hasNext()) {
                 name = navigatorIterator.next();
                 count = hostNavigator.get(name);
-                nav = "site:" + name;
+                nav = "site%3A" + name;
                 queryStringForUrl = theQuery.queryStringForUrl();
                 p = queryStringForUrl.indexOf(nav);
-                prop.put("nav-domains_element_" + i + "_on", 1);
-                prop.put(fileType, "nav-domains_element_" + i + "_modifier", nav);
+                if (p < 0) {
+                    queryStringForUrl += "+" + nav;
+                    prop.put("nav-domains_element_" + i + "_on", 1);
+                    prop.put(fileType, "nav-domains_element_" + i + "_modifier", nav);
+                } else {
+                    queryStringForUrl = (queryStringForUrl.substring(0, p) + queryStringForUrl.substring(p + nav.length())).trim();
+                    prop.put("nav-authors_element_" + i + "_on", 0);
+                    prop.put(fileType, "nav-authors_element_" + i + "_modifier", "-" + nav);
+                }
                 prop.put(fileType, "nav-domains_element_" + i + "_name", name);
-                prop.put(fileType, "nav-domains_element_" + i + "_url", QueryParams.navurl(fileType.name().toLowerCase(), 0, theQuery, queryStringForUrl + "+" + nav, theQuery.urlMask.toString(), theQuery.navigators).toString());
+                prop.put(fileType, "nav-domains_element_" + i + "_url", QueryParams.navurl(fileType.name().toLowerCase(), 0, theQuery, queryStringForUrl, theQuery.urlMask.toString(), theQuery.navigators).toString());
                 prop.put("nav-domains_element_" + i + "_count", count);
                 prop.put("nav-domains_element_" + i + "_nl", 1);
                 i++;
@@ -133,13 +146,20 @@ public class yacysearchtrailer {
             while (i < 20 && navigatorIterator.hasNext()) {
                 name = navigatorIterator.next().trim();
                 count = authorNavigator.get(name);
-                nav = (name.indexOf(' ', 0) < 0) ? "author:" + name : "author:%" + name.replace(" ", "+") + "%";
+                nav = (name.indexOf(' ', 0) < 0) ? "author%3A" + name : "author%3A%28" + name.replace(" ", "+") + "%29";
                 queryStringForUrl = theQuery.queryStringForUrl();
                 p = queryStringForUrl.indexOf(nav);
-                prop.put("nav-authors_element_" + i + "_on", 1);
-                prop.put(fileType, "nav-authors_element_" + i + "_modifier", nav);
+                if (p < 0) {
+                    queryStringForUrl += "+" + nav;
+                    prop.put("nav-authors_element_" + i + "_on", 1);
+                    prop.put(fileType, "nav-authors_element_" + i + "_modifier", nav);
+                } else {
+                    queryStringForUrl = (queryStringForUrl.substring(0, p) + queryStringForUrl.substring(p + nav.length())).trim();
+                    prop.put("nav-authors_element_" + i + "_on", 0);
+                    prop.put(fileType, "nav-authors_element_" + i + "_modifier", "-" + nav);
+                }
                 prop.put(fileType, "nav-authors_element_" + i + "_name", name);
-                prop.put(fileType, "nav-authors_element_" + i + "_url", QueryParams.navurl(fileType.name().toLowerCase(), 0, theQuery, queryStringForUrl + "+" + nav, theQuery.urlMask.toString(), theQuery.navigators).toString());
+                prop.put(fileType, "nav-authors_element_" + i + "_url", QueryParams.navurl(fileType.name().toLowerCase(), 0, theQuery, queryStringForUrl, theQuery.urlMask.toString(), theQuery.navigators).toString());
                 prop.put("nav-authors_element_" + i + "_count", count);
                 prop.put("nav-authors_element_" + i + "_nl", 1);
                 i++;
@@ -200,7 +220,7 @@ public class yacysearchtrailer {
                 } else {
                     queryStringForUrl = (queryStringForUrl.substring(0, p) + queryStringForUrl.substring(p + nav.length())).trim();
                     prop.put("nav-protocols_element_" + i + "_on", 0);
-                    prop.put(fileType, "nav-protocols_element_" + i + "_modifier", nav);
+                    prop.put(fileType, "nav-protocols_element_" + i + "_modifier", "-" + nav);
                 }
                 prop.put(fileType, "nav-protocols_element_" + i + "_name", name);
                 prop.put(fileType, "nav-protocols_element_" + i + "_url", QueryParams.navurl(fileType.name().toLowerCase(), 0, theQuery, queryStringForUrl, theQuery.urlMask.toString(), theQuery.navigators).toString());
diff --git a/source/net/yacy/search/query/RWIProcess.java b/source/net/yacy/search/query/RWIProcess.java
index 1238987fe..d72013d63 100644
--- a/source/net/yacy/search/query/RWIProcess.java
+++ b/source/net/yacy/search/query/RWIProcess.java
@@ -795,9 +795,6 @@ public final class RWIProcess extends Thread
         if ( !this.query.navigators.equals("all") && this.query.navigators.indexOf("namespace", 0) < 0 ) {
             return new ClusteredScoreMap<String>();
         }
-        if ( this.namespaceNavigator.sizeSmaller(2) ) {
-            this.namespaceNavigator.clear(); // navigators with one entry are not useful
-        }
         return this.namespaceNavigator;
     }
 
@@ -825,9 +822,6 @@ public final class RWIProcess extends Thread
                 }
             }
         }
-        if ( result.sizeSmaller(2) ) {
-            result.clear(); // navigators with one entry are not useful
-        }
         return result;
     }
 
@@ -939,9 +933,6 @@ public final class RWIProcess extends Thread
         if ( !this.query.navigators.equals("all") && this.query.navigators.indexOf("authors", 0) < 0 ) {
             return new ConcurrentScoreMap<String>();
         }
-        if ( this.authorNavigator.sizeSmaller(2) ) {
-            this.authorNavigator.clear(); // navigators with one entry are not useful
-        }
         return this.authorNavigator;
     }