diff --git a/Doc/Sda1/prerequisites.xml b/Doc/Sda1/prerequisites.xml
index aa0413a9aed12be4c1f7b47c3769eeb4f8095f4a..8ac4d00e49be9aaeb48ccbf7001358b7ab88405d 100644
--- a/Doc/Sda1/prerequisites.xml
+++ b/Doc/Sda1/prerequisites.xml
@@ -10,7 +10,7 @@
          xmlns:db="http://docbook.org/ns/docbook">
   <title>Prerequisites</title>
 
-  <section xml:id="resources">
+  <section xml:id="sda1_sect_resources">
     <title>Lecture related resources</title>
 
     <glosslist>
diff --git a/Doc/Sdi/unixIntro.xml b/Doc/Sdi/unixIntro.xml
index e46707a52522c31afe177d8bbb3e575eb699fa54..887ad1f47626e5339cd5b2c2e235575f2d4526d0 100644
--- a/Doc/Sdi/unixIntro.xml
+++ b/Doc/Sdi/unixIntro.xml
@@ -4,11 +4,20 @@
          xmlns:xlink="http://www.w3.org/1999/xlink"
          xmlns:xi="http://www.w3.org/2001/XInclude"
          xmlns:svg="http://www.w3.org/2000/svg"
+         xmlns:ns="http://docbook.org/ns/transclusion"
          xmlns:m="http://www.w3.org/1998/Math/MathML"
          xmlns:html="http://www.w3.org/1999/xhtml"
          xmlns:db="http://docbook.org/ns/docbook">
   <title>UNIX / LINUX Basics</title>
 
+  <para>This lecture targets the administration of complex software
+  infrastructures. You will learn about common building blocks providing
+  services to organisations like e.g. <xref linkend="glo_DNS"/>,
+  authentication infrastructures, network file systems and so on.</para>
+
+  <para>You'll have a hands-on access to selected examples of modern
+  infrastructure components.</para>
+
   <section xml:id="sdiUnixIntroPrerequisites">
     <title>Prerequisites</title>
 
@@ -36,7 +45,7 @@
 
           <itemizedlist>
             <listitem>
-              <para>Public/private keys, passphrases</para>
+              <para>Public/private keys, pass phrases</para>
             </listitem>
 
             <listitem>
diff --git a/Doc/Tdoc/general.xml b/Doc/Tdoc/general.xml
index 3e209c12eb5f4f86839683292a816cf287842d34..3d21452e9ead32292aa4ec10afa0cf95c03bd72a 100644
--- a/Doc/Tdoc/general.xml
+++ b/Doc/Tdoc/general.xml
@@ -11,8 +11,33 @@
          xmlns:db="http://docbook.org/ns/docbook">
   <title>Software independent considerations</title>
 
-  <para>In the next sections we will describe common building blocks of
-  (technical) documents.</para>
+  <para>This lecture predominantly targets using XML as a means for
+  representing documents. </para>
+
+  <para>XML is widely used providing persistence for various low level office
+  formats like e.g. <productname
+  xlink:href="https://www.libreoffice.org">LibreOffice</productname> or
+  Microsoft Office. On the contrary this lecture we will consider XML document
+  related dialects providing a substantial level of semantic information to
+  the respective authors. This addresses the following cross-cutting
+  concerns:</para>
+
+  <itemizedlist>
+    <listitem>
+      <para>Software vendor independence.</para>
+    </listitem>
+
+    <listitem>
+      <para>Single source publishing to different target formats.</para>
+    </listitem>
+
+    <listitem>
+      <para>Maintaining complex documentation by multiple authors.</para>
+    </listitem>
+  </itemizedlist>
+
+  <para>We will discuss schema grammars, transformation engines for different
+  target formats and editors.</para>
 
   <section xml:id="tdocSectGeneralRemarks">
     <title>General remarks</title>