diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index 9411ea2e038..c618e403f71 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -1602,14 +1602,23 @@
ConditionControlGroupController=
Check whether given cgroup controllers (e.g. cpu) are available
- for use on the system.
+ for use on the system or whether the legacy v1 cgroup or the modern v2 cgroup hierarchy is used.
+
Multiple controllers may be passed with a space separating them; in this case the condition
will only pass if all listed controllers are available for use. Controllers unknown to systemd are
- ignored. Valid controllers are cpu, cpuset,
- io, memory, and pids. Even if available in
- the kernel, a particular controller may not be available if it was disabled on the kernel command
- line with cgroup_disable=controller.
+ ignored. Valid controllers are cpu, io,
+ memory, and pids. Even if available in the kernel, a
+ particular controller may not be available if it was disabled on the kernel command line with
+ cgroup_disable=controller.
+
+ Alternatively, two special strings v1 and v2 may be
+ specified (without any controller names). v2 will pass if the unified v2 cgroup
+ hierarchy is used, and v1 will pass if the legacy v1 hierarchy or the hybrid
+ hierarchy are used. Note that legacy or hybrid hierarchies have been deprecated. See
+ systemd1 for
+ more information.
+