diff --git a/man2/sigaction.2 b/man2/sigaction.2
index 4e23711ef..7fea1f8b4 100644
--- a/man2/sigaction.2
+++ b/man2/sigaction.2
@@ -42,7 +42,7 @@
 .\" 2010-06-11 Andi Kleen, add hwpoison signal extensions
 .\" 2010-06-11 mtk, improvements to discussion of various siginfo_t fields.
 .\"
-.TH SIGACTION 2 2011-09-08 "Linux" "Linux Programmer's Manual"
+.TH SIGACTION 2 2012-04-12 "Linux" "Linux Programmer's Manual"
 .SH NAME
 sigaction \- examine and change a signal action
 .SH SYNOPSIS
@@ -421,7 +421,8 @@ and
 .I si_addr_lsb
 are Linux-specific extensions.
 .IP *
-.BR SIGPOLL / SIGIO
+.BR SIGIO / SIGPOLL
+(the two names are synonyms on Linux)
 fills in
 .IR si_band " and " si_fd .
 The
@@ -464,7 +465,13 @@ POSIX message queue state changed (since Linux 2.6.6); see
 AIO completed
 .TP
 .B SI_SIGIO
-queued SIGIO
+Queued
+.B SIGIO
+(only in kernels up to Linux 2.2; from Linux 2.4 onward
+.BR SIGIO / SIGPOLL
+fills in
+.I si_code
+as described below).
 .TP
 .B SI_TKILL
 .BR tkill (2)
@@ -626,7 +633,7 @@ stopped child has continued (since Linux 2.6.9)
 The following values can be placed in
 .I si_code
 for a
-.B SIGPOLL
+.BR SIGIO / SIGPOLL
 signal:
 .RS 4
 .TP 15