diff --git a/src/main/java/fr/plil/sio/persistence/api/GroupService.java b/src/main/java/fr/plil/sio/persistence/api/GroupService.java
index c059914..93dc768 100644
--- a/src/main/java/fr/plil/sio/persistence/api/GroupService.java
+++ b/src/main/java/fr/plil/sio/persistence/api/GroupService.java
@@ -9,7 +9,7 @@ public interface GroupService {
      * @param name the name of the group
      * @return an instance of the group
      * @throws IllegalArgumentException if name is null
-     * @throws IllegalStateException    if a group with the same name is already present
+     * @throws IllegalStateException if a group with the same name is already present
      */
     Group create(String name);
 
diff --git a/src/main/java/fr/plil/sio/persistence/api/RightService.java b/src/main/java/fr/plil/sio/persistence/api/RightService.java
index 8379d85..469cdbc 100644
--- a/src/main/java/fr/plil/sio/persistence/api/RightService.java
+++ b/src/main/java/fr/plil/sio/persistence/api/RightService.java
@@ -24,11 +24,11 @@ public interface RightService {
     Right create(String name, Right parent);
 
     /**
-     * Delete a right in the database.
+     * Delete a right in the database. Delete sibling rights if present.
      *
      * @param right the right to delete
-     * @return true if right has been deleted
-     * @throws IllegalArgumentException if right is null or if right is not found in the database.
+     * @return true if right has been deleted, false else.
+     * @throws IllegalArgumentException if right is null.
      */
     boolean delete(Right right);
 
diff --git a/src/main/java/fr/plil/sio/persistence/api/UserService.java b/src/main/java/fr/plil/sio/persistence/api/UserService.java
index 63e47a8..f488e6f 100644
--- a/src/main/java/fr/plil/sio/persistence/api/UserService.java
+++ b/src/main/java/fr/plil/sio/persistence/api/UserService.java
@@ -7,6 +7,7 @@ public interface UserService {
      * There is no two users with the same name in the database.
      *
      * @param name the name of the user
+     * @param groupName the name of the group
      * @return an instance of the user
      * @throws IllegalArgumentException if name or groupName is null, or if group does not exist.
      * @throws IllegalStateException    if an user with the same name is already present
--
libgit2 0.21.2