diff --git a/src/ejabberd_options_doc.erl b/src/ejabberd_options_doc.erl
index 5494cc12c..50bccf7a0 100644
--- a/src/ejabberd_options_doc.erl
+++ b/src/ejabberd_options_doc.erl
@@ -36,14 +36,14 @@ doc() ->
      {listen,
       #{value => "[Options, ...]",
         desc =>
-            ?T("The option for listeners configuration. See "
-               "<<listeners,Listeners>> section of this document "
+            ?T("The option for listeners configuration. See the "
+               "http://../listen/[Listen Modules] section "
                "for details.")}},
      {modules,
       #{value => "{Module: Options}",
         desc =>
             ?T("The option for modules configuration. See "
-               "<<modules,Modules>> section of this document "
+               "http://../modules/[Modules] section "
                "for details.")}},
      {loglevel,
       #{value =>
@@ -355,11 +355,12 @@ doc() ->
                "at least one of the methods succeeds. "
                "The default value is '[mnesia]'.")}},
      {auth_opts,
-      #{desc =>
-            ?T("This option is used by the contributed module "
+      #{value => "[Option, ...]",
+        desc =>
+            ?T("This is used by the contributed module "
 	       "'ejabberd_auth_http' that can be installed from the "
 	       "'ejabberd-contrib' Git repository. Please refer to that "
-	       "module's README file for details about this option.")}},
+	       "module's README file for details.")}},
      {auth_password_format,
       #{value => "plain | scram",
         desc =>
@@ -445,7 +446,8 @@ doc() ->
                "any given JID. The option is intended to protect the server "
                "from CAPTCHA DoS. The default value is 'infinity'.")}},
      {captcha_host,
-      #{desc => ?T("Deprecated. Use 'captcha_url' instead.")}},
+      #{value => "String",
+        desc => ?T("Deprecated. Use 'captcha_url' instead.")}},
      {captcha_url,
       #{value => ?T("URL"),
         desc =>
diff --git a/src/mod_mqtt.erl b/src/mod_mqtt.erl
index b2f4ded68..1bc75aa15 100644
--- a/src/mod_mqtt.erl
+++ b/src/mod_mqtt.erl
@@ -267,7 +267,8 @@ listen_options() ->
 mod_doc() ->
     #{desc =>
           ?T("This module adds support for the MQTT protocol "
-             "version '3.1.1' and '5.0'."),
+             "version '3.1.1' and '5.0'. Remember to configure "
+	     "'mod_mqtt' in 'modules' and  'listen' sections."),
       opts =>
           [{access_subscribe,
             #{value => "{TopicFilter: AccessName}",
diff --git a/src/mod_register_web.erl b/src/mod_register_web.erl
index 15eb58e75..9def83fda 100644
--- a/src/mod_register_web.erl
+++ b/src/mod_register_web.erl
@@ -627,7 +627,7 @@ mod_doc() ->
            ?T("- Delete an existing account on the server."), "",
 	   ?T("This module supports CAPTCHA image to register a new account. "
 	      "To enable this feature, configure the options 'captcha\_cmd' "
-	      "and 'captcha\_host', which are documented in the section with "
+	      "and 'captcha\_url', which are documented in the section with "
 	      "top-level options."), "",
 	   ?T("As an example usage, the users of the host 'example.org' can "
 	      "visit the page: 'https://example.org:5281/register/' It is "