diff --git a/htroot/api/webstructure.java b/htroot/api/webstructure.java
index bc1b24aff..f43418499 100644
--- a/htroot/api/webstructure.java
+++ b/htroot/api/webstructure.java
@@ -45,8 +45,51 @@ import net.yacy.search.index.Segment.ReferenceReportCache;
 import net.yacy.server.serverObjects;
 import net.yacy.server.serverSwitch;
 
+/**
+ * Retrieval of a web links structure.
+ */
 public class webstructure {
 
+	/**
+	 * Retrieve the locally known web links structure of a specified resource ("about" parameter supplied) or
+	 * the whole computed links structure since install (no parameter supplied)
+	 * or since last start or last call ("latest" parameter supplied).
+	 * Returned object contains the following information :
+	 * <ul>
+	 * 	<li>in all cases :
+	 * 		<ul>
+	 * 			<li>accumulated list of outgoing links to other domains (per host accumulated anchors)</li>
+	 * 		</ul>
+	 * 	</li>
+	 *  <li>when "about" parameter is filled :
+	 *  	<ul>
+	 * 			<li>accumulated list of incoming links from other domains (per host accumulated references)</li>
+	 * 			<li>detailed list of outgoing links (anchors) from documents to references</li>
+     * 			<li>detailed list of incoming links (citations) from other documents (their references) - reverse link structure</li>
+     * 		</ul>
+     * 	</li>
+	 * </ul>
+	 * Information detail is limited by {@link WebStructureGraph#maxhosts} and {@link WebStructureGraph#maxref} constants.
+	 * 
+	 * @param header
+	 *            servlet request header
+	 * @param post
+	 *            request parameters. Supported keys :
+	 *            <ul>
+	 *            <li>about : get only links structure about the resource
+	 *            specified as value. Supported values : host hash, URL hash,
+	 *            host name or URL</li>
+	 *            <li>latest (ignored when about parameter is valued): get the structure that have been computed during
+	 *            the current run-time of YaCy, and with each next call only an
+	 *            update to the next list of references.</li>
+	 *            <li>agentName : name of the user agent string used to load the
+	 *            "about" resource</li>
+	 *            </ul>
+	 * @param env
+	 *            server environment
+	 * @return the servlet answer object
+	 * @see WebStructureGraph
+	 */
     public static serverObjects respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
         final serverObjects prop = new serverObjects();
         final Switchboard sb = (Switchboard) env;
diff --git a/source/net/yacy/peers/graphics/WebStructureGraph.java b/source/net/yacy/peers/graphics/WebStructureGraph.java
index ddce09833..769545ab4 100644
--- a/source/net/yacy/peers/graphics/WebStructureGraph.java
+++ b/source/net/yacy/peers/graphics/WebStructureGraph.java
@@ -1,4 +1,4 @@
-// plasmaWebStructure.java
+// WebStructureGraph.java
 // -----------------------------
 // (C) 2007 by Michael Peter Christen; mc@yacy.net, Frankfurt a. M., Germany
 // first published 15.05.2007 on http://yacy.net
@@ -65,19 +65,34 @@ import net.yacy.kelondro.rwi.ReferenceFactory;
 import net.yacy.kelondro.util.FileUtils;
 import net.yacy.search.Switchboard;
 
+/**
+ * Holds lists of links per host names to allow reconstructing a web graph structure of links.
+ */
 public class WebStructureGraph {
 
-    public static int maxref = 200; // maximum number of references, to avoid overflow when a large link farm occurs (i.e. wikipedia)
-    public static int maxhosts = 10000; // maximum number of hosts in web structure map
+	/** Maximum number of references per host, to avoid overflow when a large link farm occurs (i.e. wikipedia) */
+    public static int maxref = 200;
+    
+    /** Maximum number of hosts in web structure map */
+    public static int maxhosts = 10000;
 
     private final static ConcurrentLog log = new ConcurrentLog("WebStructureGraph");
 
+    /** Backup file */
     private final File structureFile;
+    /** Older structure entries (notably loaded from the backup file) */
     private final TreeMap<String, byte[]> structure_old; // <b64hash(6)>','<host> to <date-yyyymmdd(8)>{<target-b64hash(6)><target-count-hex(4)>}*
+    
+    /** Recently computed structure entries */
     private final TreeMap<String, byte[]> structure_new;
+    
+    /** Queue used to receive new entries to store */
     private final BlockingQueue<LearnObject> publicRefDNSResolvingQueue;
+    
+    /** Worker thread consuming the publicRefDNSResolvingQueue */
     private final PublicRefDNSResolvingProcess publicRefDNSResolvingWorker;
 
+    /** Entry used to terminate the worker thread */
     private final static LearnObject leanrefObjectPOISON = new LearnObject(null, null);
 
     private static class LearnObject {
@@ -90,6 +105,13 @@ public class WebStructureGraph {
         }
     }
 
+	/**
+	 * Constructs an instance, eventually loads entries from the supplied backup
+	 * structureFile when it exists and starts the worker thread.
+	 * 
+	 * @param structureFile
+	 *            backup file
+	 */
     public WebStructureGraph(final File structureFile) {
         this.structure_old = new TreeMap<String, byte[]>();
         this.structure_new = new TreeMap<String, byte[]>();