@@ -34,6 +34,60 @@ The settings currently supported are:

  * path of devices

  * args

+## What is settable ?

+

+Look at the plugin manifest, it's easy to see what fields are settable,

+by looking at the `Settable` field.

+

+Here is an extract of a plugin manifest:

+

+```

+{

+        "config": {

+            ...

+            "args": {

+                "name": "myargs",

+                "settable": ["value"],

+                "value": ["foo", "bar"]

+            },

+            "env": [

+                {

+                    "name": "DEBUG",

+                    "settable": ["value"],

+                    "value": "0"

+                },

+                {

+                    "name": "LOGGING",

+                    "value": "1"

+                }

+            ],

+	    "devices": [

+                {

+                    "name": "mydevice",

+                    "path": "/dev/foo",

+                    "settable": ["path"]

+                }

+            ],

+	    "mounts": [

+                {

+                    "destination": "/baz",

+                    "name": "mymount",

+                    "options": ["rbind"],

+                    "settable": ["source"],

+                    "source": "/foo",

+                    "type": "bind"

+                }

+            ],

+	    ...

+	 }

+}

+```

+

+In this example, we can see that the `value` of the `DEBUG` environment variable is settable,

+the `source` of the `mymount` mount is also settable. Same for the `path` of `mydevice` and `value` of `myargs`.

+

+On the contrary, the `LOGGING` environment variable doesn't have any settable field, which implies that user cannot tweak it.

+

 ## Examples

 ### Change an environment variable

@@ -43,7 +97,6 @@ The following example change the env variable `DEBUG` on the

 ```bash

 $ docker plugin inspect -f {{.Settings.Env}} tiborvass/sample-volume-plugin

-

 [DEBUG=0]

 $ docker plugin set tiborvass/sample-volume-plugin DEBUG=1

@@ -90,13 +143,13 @@ $ docker plugin inspect -f '{{with $device := index .Settings.Devices 0}}{{$devi

 ### Change the source of the arguments

-The following example change the source of the args on the `myplugin` plugin.

+The following example change the value of the args on the `myplugin` plugin.

 ```bash

 $ docker plugin inspect -f '{{.Settings.Args}}' myplugin

 ["foo", "bar"]

-$ docker plugins set myplugin args="foo bar baz"

+$ docker plugins set myplugin myargs="foo bar baz"

 $ docker plugin inspect -f '{{.Settings.Args}}' myplugin

 ["foo", "bar", "baz"]