diff --git a/doc/source/userdoc/registering_image.rst b/doc/source/userdoc/registering_image.rst
index 10eda453..c49af714 100644
--- a/doc/source/userdoc/registering_image.rst
+++ b/doc/source/userdoc/registering_image.rst
@@ -1,16 +1,16 @@
 Registering an Image
 ====================
 
-Sahara deploys a cluster of machines based on images stored in Glance.
-Each plugin has its own requirements on image contents, see specific plugin
-documentation for details. A general requirement for an image is to have the
-cloud-init package installed.
+Sahara deploys a cluster of machines using images stored in Glance.
+Each plugin has its own requirements on the image contents (see specific plugin
+documentation for details). Two general requirements for an image are to have the
+cloud-init and the ssh-server packages installed.
 
-Sahara requires the image to be registered in the Sahara Image Registry in order to work with it.
+Sahara requires the images to be registered in the Sahara Image Registry.
 A registered image must have two properties set:
 
 * username - a name of the default cloud-init user.
 * tags - certain tags mark image to be suitable for certain plugins.
 
-The username depends on the image that is used and tags depend on the plugin used.
+The username depends on the image that is used and the tags depend on the plugin used.
 You can find both in the respective plugin's documentation.