Merge branch 'anders/diameter/doc/OTP-11519' into maint

* anders/diameter/doc/OTP-11519:
  Assorted doc fixes/tweaks

1 files changed, 75 insertions, 75 deletions

diff --git a/lib/diameter/doc/src/diameter.xml b/lib/diameter/doc/src/diameter.xml
index 726343abb2..9864b21bc5 100644
--- a/lib/diameter/doc/src/diameter.xml
+++ b/lib/diameter/doc/src/diameter.xml
@@ -130,7 +130,7 @@ ExtraArgs = list()
 <p>
 A module implementing the callback interface defined in &man_app;,
 along with any
-extra arguments to be appended to those documented for the interface.
+extra arguments to be appended to those documented.
 Note that extra arguments specific to an outgoing request can be
 specified to &call;, in which case
 those are are appended to any module-specific extra arguments.</p>
@@ -138,7 +138,7 @@ those are are appended to any module-specific extra arguments.</p>
 <p>
 Specifying a <c>#diameter_callback{}</c> record allows individual
 functions to be configured in place of the usual &man_app; callbacks.
-See that module for details.</p>
+See <c>diameter_callback.erl</c> for details.</p>
 
 <marker id="application_opt"/>
 </item>
@@ -155,7 +155,7 @@ Has one the following types.</p>
 <tag><c>{alias, &application_alias;}</c></tag>
 <item>
 <p>
-An unique identifier for the application in the scope of the
+A unique identifier for the application in the scope of the
 service.
 Defaults to the value of the <c>dictionary</c> option if
 unspecified.</p>
@@ -166,8 +166,8 @@ unspecified.</p>
 <p>
 The name of an encode/decode module for the Diameter
 messages defined by the application.
-These modules are generated from a specification file whose format is
-documented in &man_dict;.</p>
+These modules are generated from files whose format is documented in
+&man_dict;.</p>
 </item>
 
 <tag><c>{module, &application_module;}</c></tag>
@@ -195,15 +195,14 @@ Specifies whether or not the &app_pick_peer;
 application callback can modify the application state.
 Defaults to <c>false</c> if unspecified.</p>
 
-<note>
+<warning>
 <p>
-&app_pick_peer; callbacks
-are serialized when these are allowed to modify state, which is a
-potential performance bottleneck.
+&app_pick_peer; callbacks are serialized when this option is <c>true</c>,
+which is a potential performance bottleneck.
 A simple Diameter client may suffer no ill effects from using mutable
 state but a server or agent that responds to incoming request should
 probably avoid it.</p>
-</note>
+</warning>
 </item>
 
 <tag><c>{answer_errors, callback|report|discard}</c></tag>
@@ -234,7 +233,7 @@ Defaults to <c>report</c> if unspecified.</p>
 <item>
 <p>
 Determines the manner in which incoming requests are handled when an
-error other than 3007, DIAMETER_APPLICATION_UNSUPPORTED (which cannot
+error other than 3007 (DIAMETER_APPLICATION_UNSUPPORTED, which cannot
 be associated with an application callback module), is detected.</p>
 
 <p>
@@ -244,7 +243,8 @@ If <c>answer</c> then even 5xxx errors are answered without a
 callback unless the connection in question has configured the RFC 3588
 common dictionary as noted below.
 If <c>callback</c> then a &app_handle_request; callback always takes
-place and the return value determines the answer sent to the peer.</p>
+place and its return value determines the answer sent to the peer, if
+any.</p>
 
 <p>
 Defaults to <c>answer_3xxx</c> if unspecified.</p>
@@ -252,13 +252,14 @@ Defaults to <c>answer_3xxx</c> if unspecified.</p>
 <note>
 <p>
 Answers sent by diameter set the E-bit in the Diameter Header.
-Since RFC 3588 allowed only 3xxx result codes in an
+Since RFC 3588 allows only 3xxx result codes in an
 <c>answer-message</c>, <c>answer</c> has the same semantics as
-<c>answer_3xxx</c> if the peer connection in question has configured
-the RFC 3588 common dictionary, <c>diameter_gen_base_rfc3588</c>.
-RFC 6733 allows both 3xxx and 5xxx result codes in an
-<c>answer-message</c> so a connection configured with the RFC 6733
-common dictionary, <c>diameter_gen_base_rfc6733</c>, does
+<c>answer_3xxx</c> when the transport in question has
+been configured with <c>diameter_gen_base_rfc3588</c> as its common
+dictionary.
+Since RFC 6733 allows both 3xxx and 5xxx result codes in an
+<c>answer-message</c>, a transport with
+<c>diameter_gen_base_rfc6733</c> as its common dictionary does
 distinguish between <c>answer_3xxx</c> and <c>answer</c>.</p>
 </note>
 </item>
@@ -291,9 +292,8 @@ Multiple options append to the argument list.</p>
 <tag><c>{filter, &peer_filter;}</c></tag>
 <item>
 <p>
-A filter to apply to the list of available peers before passing them to
-the &app_pick_peer;
-callback for the application in question.
+A filter to apply to the list of available peers before passing it to
+the &app_pick_peer; callback for the application in question.
 Multiple options are equivalent a single <c>all</c> filter on the
 corresponding list of filters.
 Defaults to <c>none</c>.</p>
@@ -312,7 +312,7 @@ Defaults to 5000.</p>
 <p>
 Causes &call; to return <c>ok</c> as
 soon as the request in
-question has been encoded instead of waiting for and returning
+question has been encoded, instead of waiting for and returning
 the result from a subsequent &app_handle_answer; or
 &app_handle_error; callback.</p>
 </item>
@@ -331,8 +331,8 @@ An invalid option will cause &call; to fail.</p>
 <p>
 AVP values sent in outgoing CER or CEA messages during capabilities
 exchange.
-Can be configured both on a service and a transport, values specified
-on the latter taking precedence over any specified on the former.
+Can be configured both on a service and a transport, values
+on the latter taking precedence.
 Has one of the following types.</p>
 
 <taglist>
@@ -358,7 +358,7 @@ question communicates an address list as described in
 Origin-State-Id is optional but will be included in outgoing messages
 sent by diameter itself: CER/CEA, DWR/DWA and DPR/DPA.
 Setting a value of <c>0</c> (zero) is equivalent to not setting a
-value as documented in &the_rfc;.
+value, as documented in &the_rfc;.
 The function &origin_state_id;
 can be used as to retrieve a value that is computed when the diameter
 application is started.</p>
@@ -370,8 +370,8 @@ application is started.</p>
 <item>
 <p>
 Inband-Security-Id defaults to the empty list, which is equivalent to a
-list containing only 0 (= NO_INBAND_SECURITY).
-If 1 (= TLS) is specified then TLS is selected if the CER/CEA received
+list containing only 0 (NO_INBAND_SECURITY).
+If 1 (TLS) is specified then TLS is selected if the CER/CEA received
 from the peer offers it.</p>
 </item>
 
@@ -437,38 +437,38 @@ Has one of the following types.</p>
 <p>
 Matches any peer.
 This is a convenience that provides a filter equivalent to no
-filter at all.</p>
+filter.</p>
 </item>
 
 <tag><c>host</c></tag>
 <item>
 <p>
-Matches only those peers whose <c>Origin-Host</c> has the same value
-as <c>Destination-Host</c> in the outgoing request in question,
+Matches only those peers whose Origin-Host has the same value
+as Destination-Host in the outgoing request in question,
 or any peer if the request does not contain
-a <c>Destination-Host</c> AVP.</p>
+a Destination-Host AVP.</p>
 </item>
 
 <tag><c>realm</c></tag>
 <item>
 <p>
-Matches only those peers whose <c>Origin-Realm</c> has the same value
-as <c>Destination-Realm</c> in the outgoing request in question,
+Matches only those peers whose Origin-Realm has the same value
+as Destination-Realm in the outgoing request in question,
 or any peer if the request does not contain
-a <c>Destination-Realm</c> AVP.</p>
+a Destination-Realm AVP.</p>
 </item>
 
 <tag><c>{host, any|&dict_DiameterIdentity;}</c></tag>
 <item>
 <p>
-Matches only those peers whose <c>Origin-Host</c> has the
+Matches only those peers whose Origin-Host has the
 specified value, or all peers if the atom <c>any</c>.</p>
 </item>
 
 <tag><c>{realm, any|&dict_DiameterIdentity;</c></tag>
 <item>
 <p>
-Matches only those peers whose <c>Origin-Realm</c> has the
+Matches only those peers whose Origin-Realm has the
 specified value, or all peers if the atom <c>any</c>.</p>
 </item>
 
@@ -477,7 +477,8 @@ specified value, or all peers if the atom <c>any</c>.</p>
 <p>
 Matches only those peers for which the specified
 <c>&evaluable;</c> returns
-<c>true</c> on the connection's <c>diameter_caps</c> record.
+<c>true</c> when applied to the connection's <c>diameter_caps</c>
+record.
 Any other return value or exception is equivalent to <c>false</c>.</p>
 </item>
 
@@ -508,10 +509,10 @@ that matches no peer.</p>
 
 <note>
 <p>
-The <c>host</c> and <c>realm</c> filters examine the
-outgoing request as passed to &call;,
-assuming that this is a record- or list-valued <c>&codec_message;</c>,
-and that the message contains at most one of each AVP.
+The <c>host</c> and <c>realm</c> filters cause the Destination-Host
+and Destination-Realm AVPs to be extracted from the
+outgoing request, assuming it to be a record- or list-valued
+<c>&codec_message;</c>, and assuming at most one of each AVP.
 If this is not the case then the <c>{host|realm, &dict_DiameterIdentity;}</c>
 filters must be used to achieve the desired result.
 An empty <c>&dict_DiameterIdentity;</c>
@@ -555,7 +556,7 @@ Can have one of the following types.</p>
 <p>
 The service is being started or stopped.
 No event precedes a <c>start</c> event.
-No event follows a <c>stop</c> event and this event
+No event follows a <c>stop</c> event, and this event
 implies the termination of all transport processes.</p>
 </item>
 
@@ -576,9 +577,8 @@ transitioned into (<c>up</c>) or out of (<c>down</c>) the OKAY
 state.
 If a <c>#diameter_packet{}</c> is present in an <c>up</c> event
 then there has been a capabilities exchange on a newly established
-transport connection and the record contains the received CER or CEA.
-Otherwise a connection has reestablished without the loss or
-connectivity.</p>
+transport connection and the record contains the received CER or
+CEA.</p>
 
 <p>
 Note that a single <c>up</c> or <c>down</c> event for a given peer
@@ -627,10 +627,10 @@ CB = &evaluable;
 </pre>
 
 <p>
-An incoming CER has been answered with the indicated result code or
+An incoming CER has been answered with the indicated result code, or
 discarded.
-<c>Caps</c> contains pairs of values for the local node and remote
-peer.
+<c>Caps</c> contains pairs of values, for the local node and remote
+peer respectively.
 <c>Pkt</c> contains the CER in question.
 In the case of rejection by a capabilities callback, the tuple
 contains the rejecting callback.</p>
@@ -647,7 +647,7 @@ Pkt  = #diameter_packet{}
 <p>
 An incoming CER contained errors and has been answered with the
 indicated result code.
-<c>Caps</c> contains only values for the local node.
+<c>Caps</c> contains values for the local node only.
 <c>Pkt</c> contains the CER in question.</p>
 </item>
 
@@ -754,7 +754,7 @@ Defines a Diameter application supported by the service.</p>
 <p>
 A service must configure one tuple for each Diameter
 application it intends to support.
-For an outgoing Diameter request, the relevant <c>&application_alias;</c> is
+For an outgoing request, the relevant <c>&application_alias;</c> is
 passed to &call;, while for an
 incoming request the application identifier in the message
 header determines the application, the identifier being specified in
@@ -778,10 +778,11 @@ be matched by corresponding &capability; configuration, of
 <item>
 <p>
 Specifies the degree to which the service allows multiple transport
-connections to the same peer.</p>
+connections to the same peer, as identified by its Origin-Host
+at capabilities exchange.</p>
 
 <p>
-If type <c>[node()]</c> then a connection is rejected if another already
+If <c>[node()]</c> then a connection is rejected if another already
 exists on any of the specified nodes.
 Types <c>false</c>, <c>node</c>, <c>nodes</c> and
 &evaluable; are equivalent to
@@ -803,7 +804,7 @@ Defaults to <c>nodes</c>.</p>
 <item>
 <p>
 Specifies a constant value <c>H</c> for the topmost <c>32-N</c> bits of
-of 32-bit End-to-End and Hop-by-Hop identifiers generated
+of 32-bit End-to-End and Hop-by-Hop Identifiers generated
 by the service, either explicitly or as a return value of a function
 to be evaluated at &start_service;.
 In particular, an identifier <c>Id</c> is mapped to a new identifier
@@ -812,11 +813,11 @@ as follows.</p>
 (H bsl N) bor (Id band ((1 bsl N) - 1))
 </pre>
 <p>
-Note that &the_rfc; requires that End-to-End identifiers remain unique
+Note that &the_rfc; requires that End-to-End Identifiers remain unique
 for a period of at least 4 minutes and that this and the call rate
-places a lower bound on the appropriate values of <c>N</c>:
-at a rate of <c>R</c> requests per second an <c>N</c>-bit counter
-traverses all of its values in <c>(1 bsl N) div (R*60)</c> minutes so
+places a lower bound on appropriate values of <c>N</c>:
+at a rate of <c>R</c> requests per second, an <c>N</c>-bit counter
+traverses all of its values in <c>(1 bsl N) div (R*60)</c> minutes, so
 the bound is <c>4*R*60 =&lt; 1 bsl N</c>.</p>
 
 <p><c>N</c> must lie in the range <c>0..32</c> and <c>H</c> must be a
@@ -829,7 +830,7 @@ Defaults to <c>{0,32}</c>.</p>
 <p>
 Multiple Erlang nodes implementing the same Diameter node should
 be configured with different sequence masks to ensure that each node
-uses a unique range of End-to-End and Hop-by-Hop identifiers for
+uses a unique range of End-to-End and Hop-by-Hop Identifiers for
 outgoing requests.</p>
 </warning>
 </item>
@@ -852,7 +853,7 @@ by the specified function, evaluated whenever a peer connection
 becomes available or a remote service requests information about local
 connections.
 The value <c>true</c> is equivalent to <c>fun &nodes;</c>.
-The value <c>node()</c> in a node list is ignored, so a collection of
+The value <c>node()</c> in a list is ignored, so a collection of
 services can all be configured to share with the same list of
 nodes.</p>
 
@@ -899,7 +900,7 @@ If <c>evaluable()</c> then only peers returned by the specified
 function are used, evaluated whenever a remote service communicates
 information about an available peer connection.
 The value <c>true</c> is equivalent to <c>fun &nodes;</c>.
-The value <c>node()</c> in a node list is ignored.</p>
+The value <c>node()</c> in a list is ignored.</p>
 
 <p>
 Defaults to <c>false</c>.</p>
@@ -1021,8 +1022,8 @@ case the corresponding callbacks are applied until either all return
 The number of milliseconds after which a transport process having an
 established transport connection will be terminated if the expected
 capabilities exchange message (CER or CEA) is not received from the peer.
-For a connecting transport, the timing of reconnection attempts is
-governed by &watchdog_timer; or &connect_timer; expiry.
+For a connecting transport, the timing of connection attempts is
+governed by &connect_timer; or &watchdog_timer; expiry.
 For a listening transport, the peer determines the timing.</p>
 
 <p>
@@ -1038,16 +1039,17 @@ Tc = &dict_Unsigned32;
 
 <p>
 For a connecting transport, the &the_rfc; Tc timer, in milliseconds.
-Note that this timer determines the frequency with which a transport
-will attempt to establish an initial connection with its peer
-following transport configuration: once an initial connection has been
-established it's &watchdog_timer; that determines the frequency of
+This timer determines the frequency with which a transport
+attempts to establish an initial connection with its peer
+following transport configuration.
+Once an initial connection has been
+established, &watchdog_timer; determines the frequency of
 reconnection attempts, as required by RFC 3539.</p>
 
 <p>
 For a listening transport, the timer specifies the time after which a
 previously connected peer will be forgotten: a connection after this time is
-regarded as an initial connection rather than a reestablishment,
+regarded as an initial connection rather than reestablishment,
 causing the RFC 3539 state machine to pass to state OKAY rather than
 REOPEN.
 Note that these semantics are not governed by the RFC and
@@ -1066,14 +1068,12 @@ transport.</p>
 <p>
 A callback invoked prior to terminating the transport process of a
 transport connection having watchdog state <c>OKAY</c>.
-Applied to <c>Reason=transport|service|application</c> and the
-<c>&transport_ref;</c> and
-<c>&app_peer;</c>
-in question, <c>Reason</c> indicating whether the diameter
-application is being stopped, the service in question is being stopped
-at &stop_service; or
-the transport in question is being removed at &remove_transport;,
-respectively.</p>
+Applied to <c>application|service|transport</c> and the
+<c>&transport_ref;</c> and <c>&app_peer;</c> in question:
+<c>application</c> indicates that the diameter application is
+being stopped, <c>service</c> that the service in question is being
+stopped by &stop_service;, and <c>transport</c> that the transport in
+question is being removed by &remove_transport;.</p>
 
 <p>
 The return value can have one of the following types.</p>