diff --git a/doc/configuration.txt b/doc/configuration.txt
index 67d273b..9e45c39 100644
--- a/doc/configuration.txt
+++ b/doc/configuration.txt
@@ -1888,6 +1888,12 @@
         listen external_bind_app1
             bind fd@${FD_APP1}
 
+  Note: regarding Linux's abstract namespace sockets, HAProxy uses the whole
+        sun_path length is used for the address length. Some other programs
+        such as socat use the string length only by default. Pass the option
+        ",unix-tightsocklen=0" to any abstract socket definition in socat to
+        make it compatible with HAProxy's.
+
   See also : "source", "option forwardfor", "unix-bind" and the PROXY protocol
              documentation, and section 5 about bind options.
 
@@ -5996,6 +6002,12 @@
         server www1_dc1 ${LAN_DC1}.101:80
         server www1_dc2 ${LAN_DC2}.101:80
 
+  Note: regarding Linux's abstract namespace sockets, HAProxy uses the whole
+        sun_path length is used for the address length. Some other programs
+        such as socat use the string length only by default. Pass the option
+        ",unix-tightsocklen=0" to any abstract socket definition in socat to
+        make it compatible with HAProxy's.
+
   See also: "default-server", "http-send-name-header" and section 5 about
              server options