diff --git a/man3/termios.3 b/man3/termios.3
index 9ffb2a255..56c21f121 100644
--- a/man3/termios.3
+++ b/man3/termios.3
@@ -779,6 +779,22 @@ Therefore, when making multiple changes
 it may be necessary to follow this call with a further call to
 .BR tcgetattr ()
 to check that all changes have been performed successfully.
+.SH CONFORMING TO
+.BR tcgetattr (),
+.BR tcsetattr (),
+.BR tcsendbreak (),
+.BR tcdrain (),
+.BR tcflush (),
+.BR tcflow (),
+.BR cfgetispeed (),
+.BR cfgetospeed (),
+.BR cfsetispeed (),
+and
+.BR cfsetospeed ()
+are specified in POSIX.1-2001.
+
+.BR cfmakeraw ()
+is non-standard, but available on the BSDs.
 .SH NOTES
 Unix V7 and several later systems have a list of baud rates
 where after the fourteen values B0, ..., B9600 one finds the