diff --git a/man3/fmax.3 b/man3/fmax.3
index f07755748..9fc15503d 100644
--- a/man3/fmax.3
+++ b/man3/fmax.3
@@ -1,9 +1,11 @@
 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
+.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
+.\"     <mtk.manpages@gmail.com>
 .\" Distributed under GPL
 .\"
-.TH FMAX 3 2002-07-28 "" "Linux Programmer's Manual"
+.TH FMAX 3 2008-07-25 "" "Linux Programmer's Manual"
 .SH NAME
-fmax, fmaxf, fmaxl \- find maximum value
+fmax, fmaxf, fmaxl \- determine maximum of two floating-point numbers
 .SH SYNOPSIS
 .B #include <math.h>
 .sp
@@ -13,13 +15,37 @@ fmax, fmaxf, fmaxl \- find maximum value
 .br
 .BI "long double fmaxl(long double " x ", long double " y );
 .sp
-Compile with \fI\-std=c99\fP; link with \fI\-lm\fP.
+Link with \fI\-lm\fP.
+.sp
+.in -4n
+Feature Test Macro Requirements for glibc (see
+.BR feature_test_macros (7)):
+.in
+.sp
+.ad l
+.BR fmax (),
+.BR fmaxf (),
+.BR fmaxl ():
+_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE; or
+.I cc\ -std=c99
+.ad b
 .SH DESCRIPTION
-Return the larger value of
+These functions return the larger value of
 .I x
 and
 .IR y .
+.SH RETURN VALUE
+These functions return the maximum of
+.I x
+and
+.IR y .
+
+If one argument is a NaN, the other argument is returned.
+
+If both arguments are NaN, a NaN is returned.
+.SH ERRORS
+No errors occur.
 .SH "CONFORMING TO"
-C99.
+C99, POSIX.1-2001.
 .SH "SEE ALSO"
 .BR fmin (3)
diff --git a/man3/fmin.3 b/man3/fmin.3
index 9a423baeb..6cf91bd8a 100644
--- a/man3/fmin.3
+++ b/man3/fmin.3
@@ -1,9 +1,11 @@
 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
+.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
+.\"     <mtk.manpages@gmail.com>
 .\" Distributed under GPL
 .\"
-.TH FMIN 3 2002-07-28 "" "Linux Programmer's Manual"
+.TH FMIN 3 2008-07-25 "" "Linux Programmer's Manual"
 .SH NAME
-fmin, fminf, fminl \- find minimum value
+fmin, fminf, fminl \- determine minimum of two floating-point numbers
 .SH SYNOPSIS
 .B #include <math.h>
 .sp
@@ -13,13 +15,37 @@ fmin, fminf, fminl \- find minimum value
 .br
 .BI "long double fminl(long double " x ", long double " y );
 .sp
-Compile with \fI\-std=c99\fP; link with \fI\-lm\fP.
+Link with \fI\-lm\fP.
+.sp
+.in -4n
+Feature Test Macro Requirements for glibc (see
+.BR feature_test_macros (7)):
+.in
+.sp
+.ad l
+.BR fmin (),
+.BR fminf (),
+.BR fminl ():
+_XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE; or
+.I cc\ -std=c99
+.ad b
 .SH DESCRIPTION
-Return the lesser value of
+These functions the lesser value of
 .I x
 and
 .IR y .
+.SH RETURN VALUE
+These functions return the minimum of
+.I x
+and
+.IR y .
+
+If one argument is a NaN, the other argument is returned.
+
+If both arguments are NaN, a NaN is returned.
+.SH ERRORS
+No errors occur.
 .SH "CONFORMING TO"
-C99.
+C99, POSIX.1-2001.
 .SH "SEE ALSO"
 .BR fmax (3)