diff --git a/admin_manual/configuration_mimetypes/index.rst b/admin_manual/configuration_mimetypes/index.rst
index 6fe17e51d..fbe509349 100644
--- a/admin_manual/configuration_mimetypes/index.rst
+++ b/admin_manual/configuration_mimetypes/index.rst
@@ -9,3 +9,11 @@ Mimetypes Management
     mimetype_aliases
     mimetype_mapping
 
+Icon retrieval
+--------------
+
+When an icon is retrieved for a mimetype, if the full mimetype cannot be found,
+the search will fallback to looking for the part before the slash. Given a file
+with the mimetype 'image/my-custom-image', if no icon exists for the full
+mimetype, the icon for 'image' will be used instead. This allows specialised
+mimetypes to fallback to generic icons when the relevant icons are unavailable.
diff --git a/admin_manual/configuration_mimetypes/mimetype_aliases.rst b/admin_manual/configuration_mimetypes/mimetype_aliases.rst
index 134632035..f8c37bf9f 100644
--- a/admin_manual/configuration_mimetypes/mimetype_aliases.rst
+++ b/admin_manual/configuration_mimetypes/mimetype_aliases.rst
@@ -6,17 +6,43 @@ possible to show more specific icons for certain mimetypes. Take as an example
 audio files. It is nicer if they show a nice audio icon instead of the default
 file icon.
 
-By default ownCloud comes with ``mimetypealiases.dist.json``. This is a
-simple json array.
-Administrators should not update this file as it will get replaced on upgrades
-of ownCloud. Instead the file ``mimetypealiases.json`` should be created and
-modified, this file has precedence over the shipped file. 
+By default ownCloud is distributed with ``config/mimetypealiases.dist.json``.
+Administrators should not modify this file, as it will be replaced when
+ownCloud is updated.
 
-Updating mimetype aliases
--------------------------
-If there is a custom ``mimetypealiases.json`` and that is edited or ownCloud is
-updated you should run::
+Adding custom aliases
+---------------------
+
+Custom mimetype aliases can be added to ``config/mimetypealiases.json``, using
+the same syntax as ``config/mimetypealiases.dist.json``. Some common mimetypes
+that may be useful in creating aliases are:
+
+image
+  Generic image
+
+image/vector
+  Vector image
+
+audio
+  Generic audio file
+
+x-office/document
+  Word processed document
+
+x-office/spreadsheet
+  Spreadsheet
+
+x-office/presentation
+  Presentation
+
+text
+  Generic text document
+
+text/code
+  Source code
+
+Once you have made changes to ``config/mimetypealiases.json``, run the
+following to propogate the changes through the system::
 
   $ ./occ maintenance:mimetypesjs
 
-This commands makes sure that the changes are propagate through the system.