diff --git conf/nutch-default.xml conf/nutch-default.xml
index b37fdc2..dad03c2 100644
--- conf/nutch-default.xml
+++ conf/nutch-default.xml
@@ -1125,7 +1125,7 @@
   <description>
   Comma-separated list of keys to be taken from the metadata to generate fields.
   Can be used e.g. for 'description' or 'keywords' provided that these values are generated
-  by a parser (see parse-metatags plugin)  
+  by a parser (see parse-metatags plugin), and property 'metatags.names'.
   </description>
 </property>
 
@@ -1133,11 +1133,12 @@
 <property>
   <name>metatags.names</name>
   <value>*</value>
-  <description> Names of the metatags to extract, separated by ';'. 
-  Use '*' to extract all metatags. Prefixes the names with 'meta_'
-  in the parse-metadata. For instance to index description and keywords, 
-  you need to activate the plugin index-metadata and set the value of the 
-  parameter 'index.metadata' to 'meta_description;meta_keywords'.
+  <description>Names of the metatags to extract, separated by ','.
+  Use '*' to extract all metatags. Prefixes the names with 'meta_' in
+  the parse-metadata. For instance, to index description and keywords,
+  you need to activate the plugins parse-metadata and index-metadata
+  and set the value of the properties 'metatags.names' and
+  'index.metadata' to 'description,keywords'.
   </description>
 </property>
 
diff --git src/java/org/apache/nutch/parse/HTMLMetaTags.java src/java/org/apache/nutch/parse/HTMLMetaTags.java
index 9a5d4de..c698916 100644
--- src/java/org/apache/nutch/parse/HTMLMetaTags.java
+++ src/java/org/apache/nutch/parse/HTMLMetaTags.java
@@ -21,6 +21,8 @@ import java.net.URL;
 import java.util.Iterator;
 import java.util.Properties;
 
+import org.apache.nutch.metadata.Metadata;
+
 /**
  * This class holds the information about HTML "meta" tags extracted from 
  * a page. Some special tags have convenience methods for easy checking.
@@ -40,7 +42,7 @@ public class HTMLMetaTags {
 
   private URL refreshHref = null;
 
-  private Properties generalTags = new Properties();
+  private Metadata generalTags = new Metadata();
 
   private Properties httpEquivTags = new Properties();
 
@@ -166,7 +168,7 @@ public class HTMLMetaTags {
    * Returns all collected values of the general meta tags. Property names are
    * tag names, property values are "content" values.
    */
-  public Properties getGeneralTags() {
+  public Metadata getGeneralTags() {
     return generalTags;
   }
 
@@ -188,13 +190,13 @@ public class HTMLMetaTags {
             + ", refreshHref=" + refreshHref + "\n"
             );
     sb.append(" * general tags:\n");
-    Iterator<?> it = generalTags.keySet().iterator();
-    while (it.hasNext()) {
-      String key = (String)it.next();
+    String[] names = generalTags.names();
+    for (String name : names) {
+      String key = name;
       sb.append("   - " + key + "\t=\t" + generalTags.get(key) + "\n");
     }
     sb.append(" * http-equiv tags:\n");
-    it = httpEquivTags.keySet().iterator();
+    Iterator<Object> it = httpEquivTags.keySet().iterator();
     while (it.hasNext()) {
       String key = (String)it.next();
       sb.append("   - " + key + "\t=\t" + httpEquivTags.get(key) + "\n");
diff --git src/plugin/index-metadata/src/java/org/apache/nutch/indexer/metadata/MetadataIndexer.java src/plugin/index-metadata/src/java/org/apache/nutch/indexer/metadata/MetadataIndexer.java
index 7ec70c1..dae39c6 100644
--- src/plugin/index-metadata/src/java/org/apache/nutch/indexer/metadata/MetadataIndexer.java
+++ src/plugin/index-metadata/src/java/org/apache/nutch/indexer/metadata/MetadataIndexer.java
@@ -19,6 +19,10 @@ package org.apache.nutch.indexer.metadata;
 
 import java.nio.ByteBuffer;
 import java.util.Collection;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.TreeMap;
 
 import org.apache.avro.util.Utf8;
 import org.apache.hadoop.conf.Configuration;
@@ -27,17 +31,18 @@ import org.apache.nutch.indexer.IndexingFilter;
 import org.apache.nutch.indexer.NutchDocument;
 import org.apache.nutch.storage.WebPage;
 import org.apache.nutch.storage.WebPage.Field;
+import org.apache.nutch.util.Bytes;
 
 /**
  * Indexer which can be configured to extract metadata from the crawldb, parse
  * metadata or content metadata. You can specify the properties "index.db",
  * "index.parse" or "index.content" who's values are comma-delimited
- * <value>key1, key2, key3</value>.
+ * <value>key1,key2,key3</value>.
  */
 
 public class MetadataIndexer implements IndexingFilter {
   private Configuration conf;
-  private static String[] parseFieldnames;
+  private static Map<Utf8,String> parseFieldnames;
   private static final String PARSE_CONF_PROPERTY = "index.metadata";
   private static final String INDEX_PREFIX = "meta_";
   private static final String PARSE_META_PREFIX = "meta_";
@@ -51,14 +56,14 @@ public class MetadataIndexer implements IndexingFilter {
 
     // add the fields from parsemd
     if (parseFieldnames != null) {
-      for (String metatag : parseFieldnames) {
-        ByteBuffer bvalues = page.getMetadata().get(new Utf8(PARSE_META_PREFIX
-            + metatag));
+      for (Entry<Utf8,String> metatag : parseFieldnames.entrySet()) {
+        ByteBuffer bvalues = page.getMetadata().get(metatag.getKey());
         if (bvalues != null) {
-          String value = new String(bvalues.array());
+          String key = metatag.getValue();
+          String value = Bytes.toString(bvalues.array());
           String[] values = value.split("\t");
           for (String eachvalue : values) {
-            doc.add(INDEX_PREFIX + metatag, eachvalue);
+            doc.add(key, eachvalue);
           }
         }
       }
@@ -69,7 +74,13 @@ public class MetadataIndexer implements IndexingFilter {
 
   public void setConf(Configuration conf) {
     this.conf = conf;
-    parseFieldnames = conf.getStrings(PARSE_CONF_PROPERTY);
+    String[] metatags = conf.getStrings(PARSE_CONF_PROPERTY);
+    parseFieldnames = new TreeMap<Utf8,String>();
+    for (int i = 0; i < metatags.length; i++) {
+      parseFieldnames.put(
+          new Utf8(PARSE_META_PREFIX + metatags[i].toLowerCase(Locale.ROOT)),
+          INDEX_PREFIX + metatags[i]);
+    }
     // TODO check conflict between field names e.g. could have same label
     // from different sources
   }
diff --git src/plugin/parse-html/src/java/org/apache/nutch/parse/html/HTMLMetaProcessor.java src/plugin/parse-html/src/java/org/apache/nutch/parse/html/HTMLMetaProcessor.java
index c57038d..383506c 100644
--- src/plugin/parse-html/src/java/org/apache/nutch/parse/html/HTMLMetaProcessor.java
+++ src/plugin/parse-html/src/java/org/apache/nutch/parse/html/HTMLMetaProcessor.java
@@ -78,7 +78,7 @@ public class HTMLMetaProcessor {
         if (nameNode != null) {
           if (contentNode != null) {
             String name = nameNode.getNodeValue().toLowerCase();
-            metaTags.getGeneralTags().setProperty(name, contentNode.getNodeValue());
+            metaTags.getGeneralTags().add(name, contentNode.getNodeValue());
             if ("robots".equals(name)) {
   
               if (contentNode != null) {
diff --git src/plugin/parse-metatags/src/java/org/apache/nutch/parse/metatags/MetaTagsParser.java src/plugin/parse-metatags/src/java/org/apache/nutch/parse/metatags/MetaTagsParser.java
index 93b446c..2aac3c6 100644
--- src/plugin/parse-metatags/src/java/org/apache/nutch/parse/metatags/MetaTagsParser.java
+++ src/plugin/parse-metatags/src/java/org/apache/nutch/parse/metatags/MetaTagsParser.java
@@ -22,6 +22,7 @@ import java.util.Enumeration;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
@@ -31,6 +32,7 @@ import org.apache.avro.util.Utf8;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.nutch.metadata.Metadata;
 import org.apache.nutch.parse.HTMLMetaTags;
 import org.apache.nutch.parse.Parse;
 import org.apache.nutch.parse.ParseFilter;
@@ -42,7 +44,7 @@ import org.w3c.dom.DocumentFragment;
 /**
  * Parse HTML meta tags (keywords, description) and store them in the parse
  * metadata so that they can be indexed with the index-metadata plugin with the
- * prefix 'metatag.'
+ * prefix 'metatag.'. Metatags are matched ignoring case.
  */
 public class MetaTagsParser implements ParseFilter {
 
@@ -59,12 +61,9 @@ public class MetaTagsParser implements ParseFilter {
     this.conf = conf;
     // specify whether we want a specific subset of metadata
     // by default take everything we can find
-    String metatags = conf.get("metatags.names", "*");
-    String[] values = metatags.split(";");
-    for (String val : values)
-      metatagset.add(val.toLowerCase());
-    if(metatagset.size()==0){
-      metatagset.add("*");
+    String[] values = conf.getStrings("metatags.names", "*");
+    for (String val : values) {
+      metatagset.add(val.toLowerCase(Locale.ROOT));
     }
   }
 
@@ -72,56 +71,53 @@ public class MetaTagsParser implements ParseFilter {
     return this.conf;
   }
 
+  /**
+   * Check whether the metatag is in the list of metatags to be indexed (or if
+   * '*' is specified). If yes, add it to parse metadata.
+   */
+  private void addIndexedMetatags(Map<CharSequence, ByteBuffer> metadata,
+      String metatag, String value) {
+    String lcMetatag = metatag.toLowerCase(Locale.ROOT);
+    if (metatagset.contains("*") || metatagset.contains(lcMetatag)) {
+      if (LOG.isDebugEnabled()) {
+        LOG.debug("Found meta tag: " + lcMetatag + "\t" + value);
+      }
+      metadata.put(new Utf8(PARSE_META_PREFIX + lcMetatag),
+          ByteBuffer.wrap(value.getBytes()));
+    }
+  }
+
   public Parse filter(String url, WebPage page, Parse parse,
       HTMLMetaTags metaTags, DocumentFragment doc) {
 
-    Map<Utf8, ByteBuffer> metadata = new HashMap<Utf8, ByteBuffer>();
+    // temporary map: cannot concurrently iterate over and modify page metadata
+    Map<CharSequence, ByteBuffer> metadata = new HashMap<CharSequence, ByteBuffer>();
 
     // check in the metadata first : the tika-parser
-    // might have stored the values there already
-    Iterator<Entry<CharSequence, ByteBuffer>> iterator = page.getMetadata().entrySet().iterator();
-    while (iterator.hasNext()) {
-      Entry<CharSequence, ByteBuffer> entry = iterator.next();
+    // might have stored the values there already.
+    // Values are then additionally stored with the prefixed key.
+    for (Entry<CharSequence, ByteBuffer> entry : page.getMetadata().entrySet()) {
       String mdName = entry.getKey().toString();
       String value = Bytes.toStringBinary(entry.getValue());
-      if (metatagset.contains("*") || metatagset.contains(mdName.toLowerCase())) {
-        // now add the metadata
-        LOG.debug("Found meta tag: '" + mdName + "', with value: '" + value
-            + "'");
-        metadata.put(new Utf8(PARSE_META_PREFIX + mdName.toLowerCase()),
-            ByteBuffer.wrap(value.getBytes()));
-      }
+      addIndexedMetatags(metadata, mdName, value);
     }
-    Iterator<Entry<Utf8, ByteBuffer>> itm = metadata.entrySet().iterator();
-    while (iterator.hasNext()) {
-      Entry<Utf8, ByteBuffer> entry = itm.next();
+
+    // add temporary metadata to page metadata
+    for (Entry<CharSequence, ByteBuffer> entry : metadata.entrySet()) {
       page.getMetadata().put(entry.getKey(), entry.getValue());
     }
 
-    Properties generalMetaTags = metaTags.getGeneralTags();
-    Iterator<Object> it = generalMetaTags.keySet().iterator();
-    while (it.hasNext()) {
+    Metadata generalMetaTags = metaTags.getGeneralTags();
+    for (String tagName : generalMetaTags.names()) {
+      // multiple values of a metadata field are separated by '\t' in storage.
       StringBuilder sb = new StringBuilder();
-      String name = (String) it.next();
-      String[] values = new String[] { (String) generalMetaTags.get(name) };
-      // The multivalues of a metadata field are saved with a separator '\t'
-      // in the storage
-      // unless there is only one entry, where no \t is appended.
-      for (String value : values) {
-        if (values.length > 1) {
-          sb.append(value).append("\t");
-        } else {
-          sb.append(value);
+      for (String value : generalMetaTags.getValues(tagName)) {
+        if (sb.length() > 0) {
+          sb.append("\t");
         }
+        sb.append(value);
       }
-      // check whether the name is in the list of what we want or if
-      // specified *
-      if (metatagset.contains("*") || metatagset.contains(name.toLowerCase())) {
-        // Add the recently parsed value of multiValued array to metadata
-        LOG.debug("Found meta tag : " + name + "\t" + sb.toString());
-        page.getMetadata().put(new Utf8(PARSE_META_PREFIX + name.toLowerCase()),
-            ByteBuffer.wrap(Bytes.toBytes(sb.toString())));
-      }
+      addIndexedMetatags(page.getMetadata(), tagName, sb.toString());
     }
 
     Properties httpequiv = metaTags.getHttpEquivTags();
@@ -129,13 +125,7 @@ public class MetaTagsParser implements ParseFilter {
     while (tagNames.hasMoreElements()) {
       String name = (String) tagNames.nextElement();
       String value = httpequiv.getProperty(name);
-      // check whether the name is in the list of what we want or if
-      // specified *
-      if (metatagset.contains("*") || metatagset.contains(name.toLowerCase())) {
-        LOG.debug("Found meta tag : " + name + "\t" + value);
-        page.getMetadata().put(new Utf8(PARSE_META_PREFIX + name.toLowerCase()),
-            ByteBuffer.wrap(value.getBytes()));
-      }
+      addIndexedMetatags(page.getMetadata(), name, value);
     }
 
     return parse;
diff --git src/plugin/parse-metatags/src/test/org/apache/nutch/parse/metatags/TestMetaTagsParser.java src/plugin/parse-metatags/src/test/org/apache/nutch/parse/metatags/TestMetaTagsParser.java
index 34192da..47e498b 100644
--- src/plugin/parse-metatags/src/test/org/apache/nutch/parse/metatags/TestMetaTagsParser.java
+++ src/plugin/parse-metatags/src/test/org/apache/nutch/parse/metatags/TestMetaTagsParser.java
@@ -140,8 +140,7 @@ public class TestMetaTagsParser {
         if (nameNode != null) {
           if (contentNode != null) {
             String name = nameNode.getNodeValue().toLowerCase();
-            metaTags.getGeneralTags().setProperty(name,
-                contentNode.getNodeValue());
+            metaTags.getGeneralTags().add(name, contentNode.getNodeValue());
           }
         }
 
diff --git src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/HTMLMetaProcessor.java src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/HTMLMetaProcessor.java
index 5f98e62..8ff00c6 100644
--- src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/HTMLMetaProcessor.java
+++ src/plugin/parse-tika/src/java/org/apache/nutch/parse/tika/HTMLMetaProcessor.java
@@ -78,7 +78,7 @@ public class HTMLMetaProcessor {
         if (nameNode != null) {
           if (contentNode != null) {
             String name = nameNode.getNodeValue().toLowerCase();
-            metaTags.getGeneralTags().setProperty(name, contentNode.getNodeValue());
+            metaTags.getGeneralTags().add(name, contentNode.getNodeValue());
             if ("robots".equals(name)) {
   
               if (contentNode != null) {