Add backward compatibility notes to some man pages.

(as suggested by Daniel Miller in GH #745)

[skip ci]

1 files changed, 9 insertions, 2 deletions

diff --git a/pcap_compile.3pcap.in b/pcap_compile.3pcap.in
index 31a64e6c..824f52b3 100644
--- a/pcap_compile.3pcap.in
+++ b/pcap_compile.3pcap.in
@@ -17,7 +17,7 @@
 .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 .\"
-.TH PCAP_COMPILE 3PCAP "25 July 2018"
+.TH PCAP_COMPILE 3PCAP "22 August 2018"
 .SH NAME
 pcap_compile \- compile a filter expression
 .SH SYNOPSIS
@@ -52,7 +52,9 @@ captured; it is used only when checking for IPv4 broadcast addresses in
 the filter program.  If the netmask of the network on which packets are
 being captured isn't known to the program, or if packets are being
 captured on the Linux "any" pseudo-interface that can capture on more
-than one network, a value of PCAP_NETMASK_UNKNOWN can be supplied; tests
+than one network, a value of
+.B PCAP_NETMASK_UNKNOWN
+can be supplied; tests
 for IPv4 broadcast addresses will fail to compile, but all other tests in
 the filter program will be OK.
 .LP
@@ -78,5 +80,10 @@ or
 may be called with
 .I p
 as an argument to fetch or display the error text.
+.SH BACKWARD COMPATIBILITY
+.PP
+The
+.B PCAP_NETMASK_UNKNOWN
+constant became available in libpcap release 1.1.0.
 .SH SEE ALSO
 pcap(3PCAP), pcap_setfilter(3PCAP), pcap_freecode(3PCAP),