diff --git a/lib/public/User/Backend/ABackend.php b/lib/public/User/Backend/ABackend.php
index 48d410737de3207ba32abc282cdabfb6c2fa365d..a110ba5202a75f7254aaf5d0ef448bed0bbf1477 100644
--- a/lib/public/User/Backend/ABackend.php
+++ b/lib/public/User/Backend/ABackend.php
@@ -35,6 +35,9 @@ abstract class ABackend implements IUserBackend, UserInterface {
 
 	/**
 	 * @deprecated 14.0.0
+	 *
+	 * @param int $actions The action to check for
+	 * @return bool
 	 */
 	public function implementsActions($actions): bool {
 		$implements = 0;
diff --git a/lib/public/User/Backend/ICheckPasswordBackend.php b/lib/public/User/Backend/ICheckPasswordBackend.php
index 858c2d8c7da340b8d8b029ec19c7e0e9367d0e7e..b28c94f1a6c4d8dc7ba61ec16a067a364efd52ee 100644
--- a/lib/public/User/Backend/ICheckPasswordBackend.php
+++ b/lib/public/User/Backend/ICheckPasswordBackend.php
@@ -30,6 +30,10 @@ namespace OCP\User\Backend;
 interface ICheckPasswordBackend {
 	/**
 	 * @since 14.0.0
+	 *
+	 * @param string $uid The username
+	 * @param string $password The password
+	 * @return string|bool The uid on success false on failure
 	 */
 	public function checkPassword(string $loginName, string $password);
 }
diff --git a/lib/public/User/Backend/ICountUsersBackend.php b/lib/public/User/Backend/ICountUsersBackend.php
index 358557920da5e793c5dc36a2d58d8592fa14e5e7..1cb46712aa0eda707cd7fc75fdbf75eabc21a142 100644
--- a/lib/public/User/Backend/ICountUsersBackend.php
+++ b/lib/public/User/Backend/ICountUsersBackend.php
@@ -31,6 +31,8 @@ interface ICountUsersBackend {
 
 	/**
 	 * @since 14.0.0
+	 *
+	 * @return int|bool The number of users on success false on failure
 	 */
 	public function countUsers();
 }
diff --git a/lib/public/User/Backend/ICreateUserBackend.php b/lib/public/User/Backend/ICreateUserBackend.php
index d3454c613c1bee02b7b91fc6ac06d8408c973aba..09a20e124530f7356ae878facf6cfb7f58103671 100644
--- a/lib/public/User/Backend/ICreateUserBackend.php
+++ b/lib/public/User/Backend/ICreateUserBackend.php
@@ -31,6 +31,10 @@ interface ICreateUserBackend {
 
 	/**
 	 * @since 14.0.0
+	 *
+	 * @param string $uid The username of the user to create
+	 * @param string $password The password of the new user
+	 * @return bool
 	 */
 	public function createUser(string $uid, string $password): bool;
 }
diff --git a/lib/public/User/Backend/IGetDisplayNameBackend.php b/lib/public/User/Backend/IGetDisplayNameBackend.php
index f703e17157a18261c1bb041741fedfa0d6b34b87..6382ddd6eb671cd674076dcc1e191e11892e93bf 100644
--- a/lib/public/User/Backend/IGetDisplayNameBackend.php
+++ b/lib/public/User/Backend/IGetDisplayNameBackend.php
@@ -31,6 +31,9 @@ interface IGetDisplayNameBackend {
 
 	/**
 	 * @since 14.0.0
+	 *
+	 * @param string $uid user ID of the user
+	 * @return string display name
 	 */
 	public function getDisplayName($uid): string;
 }
diff --git a/lib/public/User/Backend/IGetHomeBackend.php b/lib/public/User/Backend/IGetHomeBackend.php
index 607070932e88b63a302c51a68b9e964e6ffbc4cf..20fcd004bba39729d51af70bb0b85883cebd4dfc 100644
--- a/lib/public/User/Backend/IGetHomeBackend.php
+++ b/lib/public/User/Backend/IGetHomeBackend.php
@@ -31,6 +31,9 @@ interface IGetHomeBackend {
 
 	/**
 	 * @since 14.0.0
+	 *
+	 * @param string $uid the username
+	 * @return string|bool Datadir on success false on failure
 	 */
 	public function getHome(string $uid);
 }
diff --git a/lib/public/User/Backend/IProvideAvatarBackend.php b/lib/public/User/Backend/IProvideAvatarBackend.php
index 9aefda0e272a4bb8ff82db2556f891c24c6e25b7..328c7450b40c2135272309a8e4605e57fbdca6c6 100644
--- a/lib/public/User/Backend/IProvideAvatarBackend.php
+++ b/lib/public/User/Backend/IProvideAvatarBackend.php
@@ -31,6 +31,9 @@ interface IProvideAvatarBackend {
 
 	/**
 	 * @since 14.0.0
+	 *
+	 * @param string $uid
+	 * @return bool
 	 */
 	public function canChangeAvatar(string $uid): bool;
 }
diff --git a/lib/public/User/Backend/ISetDisplayNameBackend.php b/lib/public/User/Backend/ISetDisplayNameBackend.php
index 23f8478282dec733dd141f2cd95f382fa3f461b4..ac41cd3e2c38ae46d643d823d67ca27d49ea079e 100644
--- a/lib/public/User/Backend/ISetDisplayNameBackend.php
+++ b/lib/public/User/Backend/ISetDisplayNameBackend.php
@@ -31,6 +31,10 @@ interface ISetDisplayNameBackend {
 
 	/**
 	 * @since 14.0.0
+	 *
+	 * @param string $uid The username
+	 * @param string $displayName The new display name
+	 * @return bool
 	 */
 	public function setDisplayName(string $uid, string $displayName): bool;
 }
diff --git a/lib/public/User/Backend/ISetPasswordBackend.php b/lib/public/User/Backend/ISetPasswordBackend.php
index ec008b33a5abfbd480fe58c444c9d36c370fe6e3..687ac5f70bb669769d6ff247fdea7528ccbdc00e 100644
--- a/lib/public/User/Backend/ISetPasswordBackend.php
+++ b/lib/public/User/Backend/ISetPasswordBackend.php
@@ -31,6 +31,10 @@ interface ISetPasswordBackend {
 
 	/**
 	 * @since 14.0.0
+	 *
+	 * @param string $uid The username
+	 * @param string $password The new password
+	 * @return bool
 	 */
 	public function setPassword(string $uid, string $password): bool;
 }