diff --git a/network.h b/network.h
index 099895bc..0b600f63 100644
--- a/network.h
+++ b/network.h
@@ -129,6 +129,26 @@ struct PlugVtable {
      * want the connection for some reason, or 0 on success.
      */
     int (*accepting)(Plug *p, accept_fn_t constructor, accept_ctx_t ctx);
+
+    /*
+     * Returns a user-facing description of the nature of the network
+     * connection being made. Used in interactive proxy authentication
+     * to announce which connection attempt is now in control of the
+     * Seat.
+     *
+     * The idea is not just to be written in natural language, but to
+     * connect with the user's idea of _why_ they think some
+     * connection is being made. For example, instead of saying 'TCP
+     * connection to 123.45.67.89 port 22', you might say 'SSH
+     * connection to [logical host name for SSH host key purposes]'.
+     *
+     * This function pointer may be NULL, or may exist but return
+     * NULL, in which case no user-facing description is available.
+     *
+     * If a non-NULL string is returned, it must be freed by the
+     * caller.
+     */
+    char *(*description)(Plug *p);
 };
 
 /* Proxy indirection layer.
@@ -236,6 +256,8 @@ static inline void plug_sent (Plug *p, size_t bufsize)
 { p->vt->sent(p, bufsize); }
 static inline int plug_accepting(Plug *p, accept_fn_t cons, accept_ctx_t ctx)
 { return p->vt->accepting(p, cons, ctx); }
+static inline char *plug_description(Plug *p)
+{ return p->vt->description ? p->vt->description(p) : NULL; }
 
 /*
  * Special error values are returned from sk_namelookup and sk_new
diff --git a/otherbackends/raw.c b/otherbackends/raw.c
index d6693244..57130dc6 100644
--- a/otherbackends/raw.c
+++ b/otherbackends/raw.c
@@ -19,6 +19,7 @@ struct Raw {
     LogContext *logctx;
     Ldisc *ldisc;
     bool sent_console_eof, sent_socket_eof, socket_connected;
+    char *description;
 
     Conf *conf;
 
@@ -115,11 +116,24 @@ static void raw_sent(Plug *plug, size_t bufsize)
     seat_sent(raw->seat, raw->bufsize);
 }
 
+static char *raw_plug_description(Plug *plug)
+{
+    Raw *raw = container_of(plug, Raw, plug);
+    return dupstr(raw->description);
+}
+
+static char *raw_backend_description(Backend *backend)
+{
+    Raw *raw = container_of(backend, Raw, backend);
+    return dupstr(raw->description);
+}
+
 static const PlugVtable Raw_plugvt = {
     .log = raw_log,
     .closing = raw_closing,
     .receive = raw_receive,
     .sent = raw_sent,
+    .description = raw_plug_description,
 };
 
 /*
@@ -151,6 +165,7 @@ static char *raw_init(const BackendVtable *vt, Seat *seat,
     raw->bufsize = 0;
     raw->socket_connected = false;
     raw->conf = conf_copy(conf);
+    raw->description = default_description(vt, host, port);
 
     raw->seat = seat;
     raw->logctx = logctx;
@@ -205,6 +220,7 @@ static void raw_free(Backend *be)
     if (raw->s)
         sk_close(raw->s);
     conf_free(raw->conf);
+    sfree(raw->description);
     sfree(raw);
 }
 
@@ -337,6 +353,7 @@ const BackendVtable raw_backend = {
     .provide_ldisc = raw_provide_ldisc,
     .unthrottle = raw_unthrottle,
     .cfg_info = raw_cfg_info,
+    .description = raw_backend_description,
     .id = "raw",
     .displayname_tc = "Raw",
     .displayname_lc = "raw",
diff --git a/otherbackends/rlogin.c b/otherbackends/rlogin.c
index 44a3f625..4e3abffe 100644
--- a/otherbackends/rlogin.c
+++ b/otherbackends/rlogin.c
@@ -23,6 +23,7 @@ struct Rlogin {
     Seat *seat;
     LogContext *logctx;
     Ldisc *ldisc;
+    char *description;
 
     Conf *conf;
 
@@ -192,11 +193,24 @@ static void rlogin_startup(Rlogin *rlogin, int prompt_result,
         ldisc_check_sendok(rlogin->ldisc);
 }
 
+static char *rlogin_plug_description(Plug *plug)
+{
+    Rlogin *rlogin = container_of(plug, Rlogin, plug);
+    return dupstr(rlogin->description);
+}
+
+static char *rlogin_backend_description(Backend *backend)
+{
+    Rlogin *rlogin = container_of(backend, Rlogin, backend);
+    return dupstr(rlogin->description);
+}
+
 static const PlugVtable Rlogin_plugvt = {
     .log = rlogin_log,
     .closing = rlogin_closing,
     .receive = rlogin_receive,
     .sent = rlogin_sent,
+    .description = rlogin_plug_description,
 };
 
 /*
@@ -232,6 +246,7 @@ static char *rlogin_init(const BackendVtable *vt, Seat *seat,
     rlogin->cansize = false;
     rlogin->prompt = NULL;
     rlogin->conf = conf_copy(conf);
+    rlogin->description = default_description(vt, host, port);
     *backend_handle = &rlogin->backend;
 
     addressfamily = conf_get_int(conf, CONF_addressfamily);
@@ -283,6 +298,7 @@ static void rlogin_free(Backend *be)
     if (rlogin->s)
         sk_close(rlogin->s);
     conf_free(rlogin->conf);
+    sfree(rlogin->description);
     sfree(rlogin);
 }
 
@@ -444,6 +460,7 @@ const BackendVtable rlogin_backend = {
     .provide_ldisc = rlogin_provide_ldisc,
     .unthrottle = rlogin_unthrottle,
     .cfg_info = rlogin_cfg_info,
+    .description = rlogin_backend_description,
     .id = "rlogin",
     .displayname_tc = "Rlogin",
     .displayname_lc = "Rlogin", /* proper name, so capitalise it anyway */
diff --git a/otherbackends/supdup.c b/otherbackends/supdup.c
index 2ec8e0f9..278e689e 100644
--- a/otherbackends/supdup.c
+++ b/otherbackends/supdup.c
@@ -73,6 +73,7 @@ struct supdup_tag
     LogContext *logctx;
     Ldisc *ldisc;
     int term_width, term_height;
+    char *description;
 
     long long ttyopt;
     long tcmxv;
@@ -641,6 +642,18 @@ static void supdup_send_config(Supdup *supdup)
     supdup_send_36bits(supdup, TTYROL);         // scroll amount
 }
 
+static char *supdup_plug_description(Plug *plug)
+{
+    Supdup *supdup = container_of(plug, Supdup, plug);
+    return dupstr(supdup->description);
+}
+
+static char *supdup_backend_description(Backend *backend)
+{
+    Supdup *supdup = container_of(backend, Supdup, backend);
+    return dupstr(supdup->description);
+}
+
 /*
 * Called to set up the Supdup connection.
 *
@@ -660,6 +673,7 @@ static char *supdup_init(const BackendVtable *x, Seat *seat,
         .closing = supdup_closing,
         .receive = supdup_receive,
         .sent = supdup_sent,
+        .description = supdup_plug_description,
     };
     SockAddr *addr;
     const char *err;
@@ -681,6 +695,7 @@ static char *supdup_init(const BackendVtable *x, Seat *seat,
     supdup->term_height = conf_get_int(supdup->conf, CONF_height);
     supdup->pinger = NULL;
     supdup->sent_location = false;
+    supdup->description = default_description(supdup->backend.vt, host, port);
     *backend_handle = &supdup->backend;
 
     switch (conf_get_int(supdup->conf, CONF_supdup_ascii_set)) {
@@ -799,6 +814,7 @@ static void supdup_free(Backend *be)
     if (supdup->pinger)
         pinger_free(supdup->pinger);
     conf_free(supdup->conf);
+    sfree(supdup->description);
     sfree(supdup);
 }
 
@@ -935,6 +951,7 @@ const BackendVtable supdup_backend = {
     .provide_ldisc = supdup_provide_ldisc,
     .unthrottle = supdup_unthrottle,
     .cfg_info = supdup_cfg_info,
+    .description = supdup_backend_description,
     .id = "supdup",
     .displayname_tc = "SUPDUP",
     .displayname_lc = "SUPDUP", /* proper name, so capitalise it anyway */
diff --git a/otherbackends/telnet.c b/otherbackends/telnet.c
index 048bb2d6..0011cf0d 100644
--- a/otherbackends/telnet.c
+++ b/otherbackends/telnet.c
@@ -178,6 +178,7 @@ struct Telnet {
     LogContext *logctx;
     Ldisc *ldisc;
     int term_width, term_height;
+    char *description;
 
     int opt_states[NUM_OPTS];
 
@@ -680,11 +681,24 @@ static void telnet_sent(Plug *plug, size_t bufsize)
     seat_sent(telnet->seat, telnet->bufsize);
 }
 
+static char *telnet_plug_description(Plug *plug)
+{
+    Telnet *telnet = container_of(plug, Telnet, plug);
+    return dupstr(telnet->description);
+}
+
+static char *telnet_backend_description(Backend *backend)
+{
+    Telnet *telnet = container_of(backend, Telnet, backend);
+    return dupstr(telnet->description);
+}
+
 static const PlugVtable Telnet_plugvt = {
     .log = telnet_log,
     .closing = telnet_closing,
     .receive = telnet_receive,
     .sent = telnet_sent,
+    .description = telnet_plug_description,
 };
 
 /*
@@ -724,6 +738,7 @@ static char *telnet_init(const BackendVtable *vt, Seat *seat,
     telnet->state = TOP_LEVEL;
     telnet->ldisc = NULL;
     telnet->pinger = NULL;
+    telnet->description = default_description(vt, host, port);
     *backend_handle = &telnet->backend;
 
     /*
@@ -813,6 +828,7 @@ static void telnet_free(Backend *be)
     if (telnet->pinger)
         pinger_free(telnet->pinger);
     conf_free(telnet->conf);
+    sfree(telnet->description);
     sfree(telnet);
 }
 /*
@@ -1081,6 +1097,7 @@ const BackendVtable telnet_backend = {
     .provide_ldisc = telnet_provide_ldisc,
     .unthrottle = telnet_unthrottle,
     .cfg_info = telnet_cfg_info,
+    .description = telnet_backend_description,
     .id = "telnet",
     .displayname_tc = "Telnet",
     .displayname_lc = "Telnet", /* proper name, so capitalise it anyway */
diff --git a/putty.h b/putty.h
index a2136a05..82ee83a8 100644
--- a/putty.h
+++ b/putty.h
@@ -680,6 +680,28 @@ struct BackendVtable {
      * connections that would be lost if this one were terminated. */
     char *(*close_warn_text)(Backend *be);
 
+    /*
+     * Returns a user-facing description of the nature of the network
+     * connection being made. Used in interactive proxy authentication
+     * to announce which connection attempt is now in control of the
+     * Seat.
+     *
+     * The idea is not just to be written in natural language, but to
+     * connect with the user's idea of _why_ they think some
+     * connection is being made. For example, instead of saying 'TCP
+     * connection to 123.45.67.89 port 22', you might say 'SSH
+     * connection to [logical host name for SSH host key purposes]'.
+     *
+     * This function pointer may be NULL, or may exist but return
+     * NULL, in which case no user-facing description is available.
+     * (Backends which are never proxied, such as pty and ConPTY, need
+     * not bother to fill this in.)
+     *
+     * If a non-NULL string is returned, it must be freed by the
+     * caller.
+     */
+    char *(*description)(Backend *be);
+
     /* 'id' is a machine-readable name for the backend, used in
      * saved-session storage. 'displayname_tc' and 'displayname_lc'
      * are human-readable names, one in title-case for config boxes,
@@ -728,6 +750,11 @@ static inline void backend_unthrottle(Backend *be, size_t bufsize)
 { be->vt->unthrottle(be, bufsize); }
 static inline int backend_cfg_info(Backend *be)
 { return be->vt->cfg_info(be); }
+static inline char *backend_description(Backend *be)
+{ return be->vt->description ? be->vt->description(be) : NULL; }
+
+char *default_description(const BackendVtable *backvt,
+                          const char *host, int port);
 
 extern const struct BackendVtable *const backends[];
 /*
diff --git a/ssh/ssh.c b/ssh/ssh.c
index 103f5795..c9ce2b0b 100644
--- a/ssh/ssh.c
+++ b/ssh/ssh.c
@@ -57,6 +57,7 @@ struct Ssh {
     char *savedhost;
     int savedport;
     char *fullhostname;
+    char *description;
 
     bool fallback_cmd;
     int exitcode;
@@ -717,11 +718,24 @@ static char *ssh_close_warn_text(Backend *be)
     return msg;
 }
 
+static char *ssh_plug_description(Plug *plug)
+{
+    Ssh *ssh = container_of(plug, Ssh, plug);
+    return dupstr(ssh->description);
+}
+
+static char *ssh_backend_description(Backend *backend)
+{
+    Ssh *ssh = container_of(backend, Ssh, backend);
+    return dupstr(ssh->description);
+}
+
 static const PlugVtable Ssh_plugvt = {
     .log = ssh_socket_log,
     .closing = ssh_closing,
     .receive = ssh_receive,
     .sent = ssh_sent,
+    .description = ssh_plug_description,
 };
 
 /*
@@ -731,17 +745,13 @@ static const PlugVtable Ssh_plugvt = {
  * freed by the caller.
  */
 static char *connect_to_host(
-    Ssh *ssh, const char *host, int port, char **realhost,
+    Ssh *ssh, const char *host, int port, char *loghost, char **realhost,
     bool nodelay, bool keepalive)
 {
     SockAddr *addr;
     const char *err;
-    char *loghost;
     int addressfamily, sshprot;
 
-    ssh_hostport_setup(host, port, ssh->conf,
-                       &ssh->savedhost, &ssh->savedport, &loghost);
-
     ssh->plug.vt = &Ssh_plugvt;
 
     /*
@@ -938,11 +948,17 @@ static char *ssh_init(const BackendVtable *vt, Seat *seat,
     ssh->cl_dummy.vt = &dummy_connlayer_vtable;
     ssh->cl_dummy.logctx = ssh->logctx = logctx;
 
+    char *loghost;
+
+    ssh_hostport_setup(host, port, ssh->conf,
+                       &ssh->savedhost, &ssh->savedport, &loghost);
+    ssh->description = default_description(vt, ssh->savedhost, ssh->savedport);
+
     random_ref(); /* do this now - may be needed by sharing setup code */
     ssh->need_random_unref = true;
 
     char *conn_err = connect_to_host(
-        ssh, host, port, realhost, nodelay, keepalive);
+        ssh, host, port, loghost, realhost, nodelay, keepalive);
     if (conn_err) {
         /* Call random_unref now instead of waiting until the caller
          * frees this useless Ssh object, in case the caller is
@@ -985,6 +1001,7 @@ static void ssh_free(Backend *be)
 #endif
 
     sfree(ssh->deferred_abort_message);
+    sfree(ssh->description);
 
     delete_callbacks_for_context(ssh); /* likely to catch ic_out_raw */
 
@@ -1247,6 +1264,7 @@ const BackendVtable ssh_backend = {
     .cfg_info = ssh_cfg_info,
     .test_for_upstream = ssh_test_for_upstream,
     .close_warn_text = ssh_close_warn_text,
+    .description = ssh_backend_description,
     .id = "ssh",
     .displayname_tc = "SSH",
     .displayname_lc = "SSH", /* proper name, so capitalise it anyway */
@@ -1273,6 +1291,7 @@ const BackendVtable sshconn_backend = {
     .cfg_info = ssh_cfg_info,
     .test_for_upstream = ssh_test_for_upstream,
     .close_warn_text = ssh_close_warn_text,
+    .description = ssh_backend_description,
     .id = "ssh-connection",
     .displayname_tc = "Bare ssh-connection",
     .displayname_lc = "bare ssh-connection",
diff --git a/utils/CMakeLists.txt b/utils/CMakeLists.txt
index 6376c0c9..97557eb6 100644
--- a/utils/CMakeLists.txt
+++ b/utils/CMakeLists.txt
@@ -11,6 +11,7 @@ add_sources_from_current_dir(utils
   conf_launchable.c
   ctrlparse.c
   debug.c
+  default_description.c
   dupcat.c
   dupprintf.c
   dupstr.c
diff --git a/utils/default_description.c b/utils/default_description.c
new file mode 100644
index 00000000..e0695ee6
--- /dev/null
+++ b/utils/default_description.c
@@ -0,0 +1,22 @@
+/*
+ * Construct a description string for a backend to use as
+ * backend_description(), or a plug as plug_description().
+ *
+ * For some backends this will be overridden: e.g. SSH prefers to
+ * think in terms of _logical_ host names (i.e. the one associated
+ * with the host key) rather than the physical details of where you're
+ * connecting to. But this default is good for simpler backends.
+ */
+
+#include "putty.h"
+
+char *default_description(const BackendVtable *backvt,
+                          const char *host, int port)
+{
+    const char *be_name = backvt->displayname_lc;
+
+    if (backvt->default_port && port == backvt->default_port)
+        return dupprintf("%s connection to %s", be_name, host);
+    else
+        return dupprintf("%s connection to %s port %d", be_name, host, port);
+}