+Remember to declare it with `&` if you wish to alter it.
+
+## Global stylesheets
+
+If your addon requires adding a stylesheet on all pages of Friendica, add the following hook:
+
+```php
+function <addon>_install()
+{
+ Addon::registerHook('head', __FILE__, '<addon>_head');
+ ...
+}
+
+
+function <addon>_head(App $a)
+{
+ $a->registerStylesheet(__DIR__ . '/relative/path/to/addon/stylesheet.css');
+}
+```
+
+`__DIR__` is the folder path of your addon.
+
+## JavaScript
+
+### Global scripts
+
+If your addon requires adding a script on all pages of Friendica, add the following hook:
+
+
+```php
+function <addon>_install()
+{
+ Addon::registerHook('footer', __FILE__, '<addon>_footer');
+ ...
+}
+
+function <addon>_footer(App $a)
+{
+ $a->registerFooterScript(__DIR__ . '/relative/path/to/addon/script.js');
+}
+```
+
+`__DIR__` is the folder path of your addon.
+
+### JavaScript hooks
+
+The main Friendica script provides hooks via events dispatched on the `document` property.
+In your Javascript file included as described above, add your event listener like this:
+
+```js
+document.addEventListener(name, callback);
+```
+
+- *name* is the name of the hook and corresponds to a known Friendica JavaScript hook.
+- *callback* is a JavaScript anonymous function to execute.
+
+More info about Javascript event listeners: https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener
+
+#### Current JavaScript hooks
+
+##### postprocess_liveupdate
+Called at the end of the live update process (XmlHttpRequest) and on a post preview.
+No additional data is provided.