diff --git a/docs/plugins/api.rst b/docs/plugins/api.rst
index 5714adf..f6fc1e9 100644
--- a/docs/plugins/api.rst
+++ b/docs/plugins/api.rst
@@ -12,9 +12,9 @@ The ``config`` attribute is used to modify existing and add new configuration pa
 
 * ``config["add"]`` are key/values that should be added to the user-specific ``config.yml`` configuration. Add there passwords, secret keys and other values that do not have a default value.
 * ``config["defaults"]`` are default key/values for this plugin. These values will not be added to the ``config.yml`` user file unless users override them manually with ``tutor config save --set ...``.
-* ``config["set"]`` are existing key/values that should be modified. Be very careful what you add there! Plugins may define conflicting values for some parameters.
+* ``config["set"]`` are existing key/values that should be modified. Be very careful what you add there! Different plugins may define conflicting values for some parameters.
 
- "set" and "default" key names will be automatically prefixed with the plugin name, in upper case.
+ "add" and "defaults" key names will be automatically prefixed with the plugin name, in upper case.
 
 Example::
 
diff --git a/tutor/plugins.py b/tutor/plugins.py
index b97733d..0be884a 100644
--- a/tutor/plugins.py
+++ b/tutor/plugins.py
@@ -19,9 +19,9 @@ class BasePlugin:
     Tutor plugins are defined by a name and an object that implements one or more of the
     following properties:
 
-    `config` (dict str->dict(str->str)): contains "add", "set", "default" keys. Entries
+    `config` (dict str->dict(str->str)): contains "add", "defaults", "set" keys. Entries
     in these dicts will be added or override the global configuration. Keys in "add" and
-    "set" will be prefixed by the plugin name in uppercase.
+    "defaults" will be prefixed by the plugin name in uppercase.
 
     `patches` (dict str->str): entries in this dict will be used to patch the rendered
     Tutor templates. For instance, to add "somecontent" to a template that includes '{{