+#### Special data
+
+Special additional data are passed to every hook through the
+`$data` parameter to give you access to additional context, and services.
+
+Complete list:
+
+ * `_PAGE_` (string): if the current hook is used to render a template, its name is passed through this additional parameter.
+ * `_LOGGEDIN_` (bool): whether the user is logged in or not.
+ * `_BASE_PATH_` (string): if Shaarli instance is hosted under a subfolder, contains the subfolder path to `index.php` (e.g. `https://domain.tld/shaarli/` -> `/shaarli/`).
+ * `_BOOKMARK_SERVICE_` (`BookmarkServiceInterface`): bookmark service instance, for advanced usage.
+
+Example:
+
+```php
+if ($data['_PAGE_'] === TemplatePage::LINKLIST && $data['LOGGEDIN'] === true) {
+ // Do something for logged in users when the link list is rendered
+}
+```
+