4 files changed, 44 insertions, 1 deletions
diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 7126fb0ed..9c03523bb 100644
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -19603,7 +19603,7 @@ so on when debugging driver configurations. For example, if a &%headers_add%&
 option is not working properly, &%debug_print%& could be used to output the
 variables it references. A newline is added to the text if it does not end with
 one.
-The variables &$transport_name$ and &$router_name$& contain the name of the
+The variables &$transport_name$& and &$router_name$& contain the name of the
 transport and the router that called it.
 
 
diff --git a/doc/doc-txt/ChangeLog b/doc/doc-txt/ChangeLog
index 3a1e39c45..2ce297fcb 100644
--- a/doc/doc-txt/ChangeLog
+++ b/doc/doc-txt/ChangeLog
@@ -156,6 +156,18 @@ PP/15 Define SIOCGIFCONF_GIVES_ADDR for GNU Hurd.
 
 SC/01 Update eximstats to watch out for senders sending 'HELO [IpAddr]'
 
+JH/14 SMTP PRDR (http://www.eric-a-hall.com/specs/draft-hall-prdr-00.txt).
+      Server implementation by Todd Lyons, client by JH.
+      Only enabled when compiled with EXPERIMENTAL_PRDR.  A new
+      config variable "prdr_enable" controls whether the server
+      advertises the facility.  If the client requests PRDR a new
+      acl_data_smtp_prdr ACL is called once for each recipient, after
+      the body content is received and before the acl_smtp_data ACL.
+      The client is controlled by bolth of: a hosts_try_prdr option
+      on the smtp transport, and the server advertisement.
+      Default client logging of deliveries and rejections involving
+      PRDR are flagged with the string "PRDR".
+
 
 Exim version 4.80.1
 -------------------
diff --git a/doc/doc-txt/NewStuff b/doc/doc-txt/NewStuff
index 70890b185..47c5f6fec 100644
--- a/doc/doc-txt/NewStuff
+++ b/doc/doc-txt/NewStuff
@@ -126,6 +126,9 @@ Version 4.82
     particularly for debug_print as -bt commandline option does not
     require privilege whereas -d does.
 
+18. If built with EXPERIMENTAL_PRDR, per-recipient data responses per a
+    proposed extension to SMTP from Eric Hall.
+
 
 Version 4.80
 ------------
diff --git a/doc/doc-txt/experimental-spec.txt b/doc/doc-txt/experimental-spec.txt
index 7bb17883c..f419bfedf 100644
--- a/doc/doc-txt/experimental-spec.txt
+++ b/doc/doc-txt/experimental-spec.txt
@@ -6,6 +6,34 @@ about experimental  features, all  of which  are unstable and
 liable to incompatible change.
 
 
+PRDR support
+--------------------------------------------------------------
+
+Per-Recipient Data Reponse is an SMTP extension proposed by Eric Hall
+in a (now-expired) IETF draft from 2007.  It's not hit mainstream
+use, but has apparently been implemented in the META1 MTA.
+
+There is mention at http://mail.aegee.org/intern/sendmail.html
+of a patch to sendmail "to make it PRDR capable".
+
+ ref: http://www.eric-a-hall.com/specs/draft-hall-prdr-00.txt
+
+If Exim is built with EXPERIMENTAL_PRDR there is a new config
+boolean "prdr_enable" which controls whether PRDR is advertised
+as part of an EHLO response, a new "acl_data_smtp_prdr" ACL
+(called for each recipient, after data arrives but before the
+data ACL), and a new smtp transport option "hosts_try_prdr".
+
+PRDR may be used to support per-user content filtering.  Without it
+one must defer any recipient after the first that has a different
+content-filter configuration.  With PRDR, the RCPT-time check
+for this can be disabled when the MAIL-time $smtp_command included
+"PRDR".  Any required difference in behaviour of the main DATA-time
+ACL should however depend on the PRDR-time ACL having run, as Exim
+will avoid doing so in some situations (eg.  single-recipient mails).
+
+
+
 OCSP Stapling support
 --------------------------------------------------------------