diff --git a/man/systemd.special.xml b/man/systemd.special.xml
index fe40da7fbe..c3c6b144d1 100644
--- a/man/systemd.special.xml
+++ b/man/systemd.special.xml
@@ -1192,6 +1192,60 @@
+
+
+ Special User Slice Units
+
+ There are four .slice units which form the basis of the user hierarchy for
+ assignment of resources for user applications and services. See
+ systemd.slice7
+ for details about slice units and the documentation about
+ Desktop Environments
+ for further information.
+
+
+
+ -.slice
+
+ The root slice is the root of the user's slice hierarchy.
+ It usually does not contain units directly, but may be used to set defaults for the whole tree.
+
+
+
+
+ app.slice
+
+ By default, all user services and applications managed by
+ systemd are found in this slice.
+ All interactively launched applications like web browsers and text editors
+ as well as non-critical services should be placed into this slice.
+
+
+
+
+ session.slice
+
+ All essential services and applications required for the
+ session should use this slice.
+ These are services that either cannot be restarted easily
+ or where latency issues may affect the interactivity of the system and applications.
+ This includes the display server, screen readers and other services such as DBus or XDG portals.
+ Such services should be configured to be part of this slice by
+ adding Slice=session.slice to their unit files.
+
+
+
+
+ background.slice
+
+ All services running low-priority background tasks should use this slice.
+ This permits resources to be preferentially assigned to the other slices.
+ Examples include non-interactive tasks like file indexing or backup operations
+ where latency is not important.
+
+
+
+