man: clarify that the controllers listed on Delegate= might not be the only ones

diff --git a/man/systemd.resource-control.xml b/man/systemd.resource-control.xml
index 1ab13ea..18b7bf8 100644 (file)
--- a/man/systemd.resource-control.xml
+++ b/man/systemd.resource-control.xml
@@ -720,9 +720,10 @@
           of control group controller names. If true, delegation is turned on, and all supported controllers are
           enabled for the unit, making them available to the unit's processes for management. If false, delegation is
           turned off entirely (and no additional controllers are enabled). If set to a list of controllers, delegation
-          is turned on, and the specified controllers are enabled for the unit. Note that assigning the empty string
-          will enable delegation, but reset the list of controllers, all assignments prior to this will have no effect.
-          Defaults to false.</para>
+          is turned on, and the specified controllers are enabled for the unit. Note that additional controllers than
+          the ones specified might be made available as well, depending on configuration of the containing slice unit
+          or other units contained in it. Note that assigning the empty string will enable delegation, but reset the
+          list of controllers, all assignments prior to this will have no effect.  Defaults to false.</para>
 
           <para>Note that controller delegation to less privileged code is only safe on the unified control group
           hierarchy. Accordingly, access to the specified controllers will not be granted to unprivileged services on