--- IO-AIO/AIO.pm	2006/10/23 00:34:36	1.63
+++ IO-AIO/AIO.pm	2006/10/23 00:50:10	1.64
@@ -542,6 +542,12 @@
 that finishing the requests in the group depends on executing the given
 code.
 
+While this request does nothing, it still goes through the execution
+phase and still requires a worker thread. Thus, the callback will not
+be executed immediately but only after other requests in the queue have
+entered their execution phase. This can be used to measure request
+latency.
+
 =item IO::AIO::aio_sleep $fractional_seconds, $callback->()  *NOT EXPORTED*
 
 Mainly used for debugging and benchmarking, this aio request puts one of