diff --git a/Doc/library/resource.rst b/Doc/library/resource.rst
--- a/Doc/library/resource.rst
+++ b/Doc/library/resource.rst
@@ -50,9 +50,11 @@
 
 .. function:: setrlimit(resource, limits)
 
-   Sets new limits of consumption of *resource*. The *limits* argument must be a
-   tuple ``(soft, hard)`` of two integers describing the new limits. A value of
-   ``-1`` can be used to specify the maximum possible upper limit.
+   Sets new limits of consumption of *resource*. The *limits* argument must be
+   a tuple ``(soft, hard)`` of two integers describing the new limits. A value
+   of ``-1`` can be used to request an infinite limit; this may result in an
+   exception if the hard limit or system limit for the specified resource is a
+   limited value.
 
    Raises :exc:`ValueError` if an invalid resource is specified, if the new soft
    limit exceeds the hard limit, or if a process tries to raise its hard limit