diff --git a/pathauto.api.php b/pathauto.api.php
index 41f1154..2cb25f1 100644
--- a/pathauto.api.php
+++ b/pathauto.api.php
@@ -11,6 +11,32 @@
 function hook_path_alias_types() {
 }
 
+/**
+ * Provide information about the way your module's aliases will be built.
+ *
+ * The information you provide here is used to build the form
+ * on search/path/patterns. File pathauto.pathauto.inc provides example
+ * implementations for system modules.
+ *
+ * @see node_pathauto
+ *
+ * @param $op
+ *   At the moment it's always 'settings'.
+ *
+ * @return
+ *   An associative array with:
+ *   - 'module': The module or entity type.
+ *   - 'token_type': Which token type should be allowed in the patterns form.
+ *   - 'groupheader': Translated label for the settings group
+ *   - 'patterndescr': The translated label for the default pattern (e.g.,
+ *      t('Default path pattern (applies to all content types with blank
+ *      patterns below)')
+ *   - 'patterndefault': Default pattern  (e.g. 'content/[node:title]'
+ *   - 'batch_update_callback': The name of function that should be ran for
+ *      bulk update. @see node_pathauto_bulk_update_batch_process for example
+ *   - 'batch_file': The name of the file with the bulk update function.
+ *   - 'patternitems': Optional. An array of descritpions keyed by bundles.
+ */
 function hook_pathauto($op) {
 }