Document reserved attributes

README.md

@@ -27,3 +27,12 @@ There is an automatic publishing process initiated for each package if code is p
 to the `master` branch, if the package isn't set to private in its `package.json` and
 the version number in its `package.json` is higher than the version number on npmjs.com.
 
+## Reserved attributes
+
+| Attribute         | Description                                                         |
+| ----------------- | ------------------------------------------------------------------- |
+| `subscribe`       | Used in all components to subscribe to attributes set by a provider |
+| `unsubscribe`     | Reserved for future use                                             |
+| `auth`            | Authentication information, set by the authentication component     |
+| `lang`            | Currently selected language, set by the language selector           |
+| `entry-point-url` | Entry point url for all api requests                                |