diff --git a/Doc/library/resource.rst b/Doc/library/resource.rst
index 4e58b043f1d..389a63f089d 100644
--- a/Doc/library/resource.rst
+++ b/Doc/library/resource.rst
@@ -177,6 +177,8 @@ platform.
 
    The largest area of mapped memory which the process may occupy.
 
+   .. availability:: FreeBSD >= 11.
+
 
 .. data:: RLIMIT_AS