diff --git a/cdist/argparse.py b/cdist/argparse.py
index ca69cdae..ed94d266 100644
--- a/cdist/argparse.py
+++ b/cdist/argparse.py
@@ -424,7 +424,7 @@ def get_parsers():
     parser['inventory'].set_defaults(
             func=cdist.inventory.Inventory.commandline)
 
-    # PreOs
+    # PreOS
     parser['preos'] = parser['sub'].add_parser('preos', add_help=False)
 
     # Shell
diff --git a/docs/src/cdist-preos.rst b/docs/src/cdist-preos.rst
index e85af2de..2f102fef 100644
--- a/docs/src/cdist-preos.rst
+++ b/docs/src/cdist-preos.rst
@@ -4,9 +4,9 @@ PreOS
 Description
 -----------
 With cdist you can install and configure new machines. You can use cdist to
-create PreOS, minimal OS which purpose is to boot new machine.
-After PreOS is booted machine is ready for installing desired OS and
-then it is ready for configuration.
+create PreOS, minimal OS whose purpose is to boot a new machine.
+After PreOS is booted, the machine is ready for installing the desired OS and
+afterwards it is ready for configuration.
 
 PreOS creation
 --------------
@@ -15,62 +15,62 @@ Currently supported PreOS-es include:
 
 * debian
 * ubuntu
-* devuan.
+* devuan
 
-PreOS is created using cdist preos command. preos command has subcommands that
-create the desired PreOS.
+PreOS is created using the ``cdist preos`` command.
+This command has subcommands that determine the desired PreOS.
 
-For example, to create ubuntu PreOS:
+For example, to create an ubuntu PreOS:
 
 .. code-block:: sh
 
     $ cdist preos ubuntu /preos/preos-ubuntu -B -C \
         -k ~/.ssh/id_rsa.pub -p /preos/pxe-ubuntu
 
-For more info about available options see cdist manual page.
+For more info about the available options see the cdist manual page.
 
-This will bootstrap (``-B``) ubuntu PreOS in ``/preos/preos-ubuntu`` directory, it
-will be configured (``-C``) using default built-in initial manifest and with
-specified ssh authorized key (``-k``).
-After bootstrapping and configuration PXE
-boot directory will be created (``-p``) in ``/preos/pxe-ubuntu``.
+This will bootstrap (``-B``) ubuntu PreOS in the ``/preos/preos-ubuntu``
+directory, it will be configured (``-C``) using default the built-in initial
+manifest and with specified ssh authorized key (``-k``).
+After bootstrapping and configuration, the PXE boot directory will be
+created (``-p``) in ``/preos/pxe-ubuntu``.
 
-After PreOS is created new machines can be booted using created PXE (after
-proper dhcp, tftp setting).
+After PreOS is created, new machines can be booted using the created PXE
+(after proper dhcp and tftp settings).
 
-Since PreOS is configured with ssh authorized key it can be accessed throguh
+Since PreOS is configured with ssh authorized key it can be accessed through
 ssh, i.e. it can be further installed and configured with cdist.
 
-Implementing new PreOS sub-command
-----------------------------------
+Implementing a new PreOS sub-command
+------------------------------------
 preos command is implemented as a plugin system. This plugin system scans for
-preos subcommands in ``cdist/preos/`` distribution directory and also in
+preos subcommands in the ``cdist/preos/`` distribution directory and also in
 ``~/.cdist/preos/`` directory if it exists.
 
 preos subcommand is a module or a class that satisfies the following:
 
-* it has attribute ``_cdist_preos`` set to ``True``
-* it has function/method ``commandline``.
+* it has the attribute ``_cdist_preos`` set to ``True``
+* it defines a function/method ``commandline``.
 
-For a module based preos subcommand ``commandline`` function accepts a module
-object as its first argument and the list of command line
+For a module-based preos subcommand, the ``commandline`` function accepts a
+module object as its first argument and the list of command line
 arguments (``sys.argv[2:]``).
 
-For a class preos subcommand ``commandline`` method should be staticmethod and
-it accepts a class object as its first argument and the list of command line
-arguments(``sys.argv[2:]``).
+For a class-based preos subcommand ``commandline`` method should be
+static-method and must accept a class as its first argument and the
+list of command line arguments (``sys.argv[2:]``).
 
 If preos scanning finds a module/class that has ``_cdist_preos`` set
-to ``True`` and it has function/method ``commandline`` then this module/class is
+to ``True`` and a function/method ``commandline`` then this module/class is
 registered to preos subcommands. The name of the command is set to ``_preos_name``
-attribute if it exists, otherwise it is set to the module/class name, lowercase.
-When registered preos subcommand is specified as preos command then ``commandline``
-will be called with first argument set to module/class object and second argument
-set to ``sys.argv[2:]``.
+attribute if defined in the module/class, defaulting to the module/class name in lowercase.
+When a registered preos subcommand is specified, ``commandline``
+will be called with the first argument set to module/class and the second
+argument set to ``sys.argv[2:]``.
 
-Example writing new dummy preos sub-command
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Module based preos:
+Example of writing new dummy preos sub-command
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Module-based preos:
 ^^^^^^^^^^^^^^^^^^^
 
 #. Create directory ``~/.cdist/preos/`` if it does not exist
@@ -134,4 +134,4 @@ When you try to run this new preos you will get:
     FreeBSD dummy preos: []
 
 In the ``commandline`` function/method you have all the freedom to actually create
-PreOS.
+a PreOS.