diff --git a/Changes b/Changes
index 9d5509f..511c3dc 100755
--- a/Changes
+++ b/Changes
@@ -13,6 +13,7 @@
           configuration option 'experimental_proxy'.
         - Updated documentation on annotations.
         - Introduced documentation on Annis QL (margaretha).
+        - Improved documentation on data.
 
 0.34 2019-06-26
         - Introduced guided tour (hebasta, #19).
diff --git a/templates/doc/data.html.ep b/templates/doc/data.html.ep
index b589435..4fd992c 100644
--- a/templates/doc/data.html.ep
+++ b/templates/doc/data.html.ep
@@ -1,5 +1,26 @@
 % layout 'main', title => 'KorAP: Data';
 
 <h2 id="tutorial-top">Data</h2>
+<p>KorAP is developed as being the main access point to
+  <%= doc_ext_link_to 'DeReKo', 'http://www1.ids-mannheim.de/kl/projekte/korpora' %>,
+  being the successor of <%= doc_ext_link_to 'COSMAS II', 'https://cosmas2.ids-mannheim.de/cosmas2-web/' %> in that regard.
+  But KorAP is not focussed on any specific corpus, it is, for example, now also used for the Romanian national corpus <%= doc_ext_link_to 'CoRoLa', 'http://corola.racai.ro/' %>.</p>
 
-<p>Under Construction</p>
+<p>In KorAP, corpus texts are allowed to have arbitrary metadata information, that partially can be used to create subcorpora (so-called virtual corpora).</p>
+
+<p>KorAP also supports an arbitrary number of <%= doc_link_to 'Annotations', 'data', 'annotation' %> from different sources (called <em>foundries</em>) with different <em>layers</em>.</p>
+
+<dl>
+  <p>Annotations of the following kind are supported:</p>
+  <dt>Tokens</dt>
+  <dd>Annotations associated to single tokens (e.g. words or numbers)</dd>
+  
+  <dt>Spans</dt>
+  <dd>Annotations to a sequence of words or nodes (e.g. sentences, phrases, constituency annotations)</dd>
+
+  <dt>Relations</dt>
+  <dd>Annotations of relations between tokens or spans (e.g. dependency annotations)</dd>
+
+  <dt>Attributes</dt>
+  <dd>Attribute information for tokens, spans, or relations (e.g. attributes of HTML elements)</dd>
+</dl>
diff --git a/templates/doc/data/corpus.html.ep b/templates/doc/data/corpus.html.ep
deleted file mode 100644
index 973b728..0000000
--- a/templates/doc/data/corpus.html.ep
+++ /dev/null
@@ -1,5 +0,0 @@
-% layout 'main', title => 'KorAP: Corpora';
-
-<h2 id="tutorial-top">Corpora</h2>
-
-%= doc_uc
diff --git a/templates/doc/navigation.json b/templates/doc/navigation.json
index 6f4fc0b..4662fc3 100644
--- a/templates/doc/navigation.json
+++ b/templates/doc/navigation.json
@@ -116,19 +116,9 @@
   {
     "title" : "Data",
     "id" : "data",
+    "class" : "folded",
     "items" : [
       {
-        "title" : "Corpora",
-        "id" : "corpus",
-        "class" : "folded",
-        "items" : [
-          {
-            "title" : "DeReKo",
-            "id" : "#dereko"
-          }
-        ]
-      },
-      {
         "title" : "Annotations",
         "id" : "annotation",
         "class" : "folded",