diff --git a/doc/INSTALL.txt b/doc/INSTALL.txt
index 572da35..04ccbcd 100644
--- a/doc/INSTALL.txt
+++ b/doc/INSTALL.txt
@@ -22,7 +22,7 @@ Installation instructions
    on the shell ("semanticscuttle" being the database name)
 
 3. Copy ``data/config.php.dist`` to ``data/config.php`` and modify it as
-   necessary.
+   necessary. See configuration_ for more information.
 4. Make the cache directory writable by your web server.
    For example, run ::
 
@@ -35,6 +35,9 @@ Installation instructions
    with your browser.
 
 
+.. _configuration: configuration.html
+
+
 Ugly www directory in URLs
 ==========================
 In case point 5 of the installation instructions cannot be put into
diff --git a/doc/configuration.rst b/doc/configuration.rst
new file mode 100644
index 0000000..f457ebb
--- /dev/null
+++ b/doc/configuration.rst
@@ -0,0 +1,58 @@
+===================
+Configuration files
+===================
+
+SemanticScuttle uses at least two configuration files:
+
+1. Default configuration file ``config.default.php``
+2. Custom configuration file ``config.php``
+
+
+The **default configuration** file contains sensible defaults for most users
+that do not need to be changed to get started.
+
+Never change it - it will get overwritten with the next update.
+If you want to change values in it, copy them into your personal
+``config.php`` file - updates to SemanticScuttle will not change that one.
+
+The **custom configuration** file, ``config.php`` is created by copying the
+shipped ``config.php.dist`` file and modifying the values in there.
+
+It consists of the configuration directives that should be set on every
+fresh installation.
+
+
+
+Configuration scenarios
+=======================
+
+Simple installation
+-------------------
+Put your configuration file in ``data/config.php``.
+If you installed SemanticScuttle's PEAR package, use::
+
+    $ pear config-get data_dir
+    /usr/share/php/data
+
+to find the data directory location and append ``SemanticScuttle/`` to it.
+In this case, the configuration file has to be in::
+
+    /usr/share/php/data/SemanticScuttle/config.php
+
+
+The configuration file may also be saved into::
+
+    /etc/semanticscuttle/config.php
+
+
+Multiple SemanticScuttle instances
+----------------------------------
+The files of one single SemanticScuttle installation may be shared
+for several SemanticScuttle instances.
+
+To be able to configure them differently, SemanticScuttle supports
+per-host configuration files:
+
+- ``data/config.$hostname.php``
+- ``/etc/semanticscuttle/config.$hostname.php``
+
diff --git a/doc/index.rst b/doc/index.rst
index 85d2ab6..0a53680 100644
--- a/doc/index.rst
+++ b/doc/index.rst
@@ -20,10 +20,12 @@ Features
 - `Custom user authentication`__
 - `SSL Client certificates`__
 - Themes__
+- `Configuration files`__
 
 __ authentication.html
 __ ssl-client-certificates.html
 __ themes.html
+__ configuration.html