diff --git a/man7/cgroups.7 b/man7/cgroups.7
index 215e2eaad..0d7bafa0c 100644
--- a/man7/cgroups.7
+++ b/man7/cgroups.7
@@ -1167,6 +1167,14 @@ cgroup by writing the string
 to the
 .I cgroup.type
 file.
+.IP
+The rationale for the existence of this "interim" type
+during the creation of a threaded subtree
+(rather than the kernel simply immediately converting all cgroups
+under the threaded root to the type
+.IR threaded )
+is to allow for
+possible future extensions to the thread mode model
 .\"
 .SS Threaded versus domain controllers
 With the addition of threads mode,