diff --git a/topics/basics/indexing_and_psi_stubs/file_based_indexes.md b/topics/basics/indexing_and_psi_stubs/file_based_indexes.md
index 0b6920a2e..d7a6d2f94 100644
--- a/topics/basics/indexing_and_psi_stubs/file_based_indexes.md
+++ b/topics/basics/indexing_and_psi_stubs/file_based_indexes.md
@@ -1,6 +1,8 @@
-[//]: # (title: File-Based Indexes)
+
-
+# File-Based Indexes
+
+Introduction to file-based indexes allowing to store information about presence of some values in files, and accessing it by keys in a performant way.
File-based indexes are based on a [Map/Reduce architecture](https://en.wikipedia.org/wiki/MapReduce).
Each index has a specific type of key and a particular type of value.
diff --git a/topics/basics/testing_plugins/light_and_heavy_tests.md b/topics/basics/testing_plugins/light_and_heavy_tests.md
index 7cfb1041e..0d6c8880e 100644
--- a/topics/basics/testing_plugins/light_and_heavy_tests.md
+++ b/topics/basics/testing_plugins/light_and_heavy_tests.md
@@ -1,6 +1,8 @@
-[//]: # (title: Light and Heavy Tests)
+
-
+# Light and Heavy Tests
+
+Introduction to light tests reusing a single project for multiple tests, and heavy tests creating a new project for each test.
Plugin tests run in a real, rather than mocked, IntelliJ Platform environment and use real implementations for most application and project [services](plugin_services.md).
diff --git a/topics/reference_guide/custom_language_support/declarations_and_references.md b/topics/reference_guide/custom_language_support/declarations_and_references.md
index cf500f886..85ca7cb05 100644
--- a/topics/reference_guide/custom_language_support/declarations_and_references.md
+++ b/topics/reference_guide/custom_language_support/declarations_and_references.md
@@ -1,6 +1,8 @@
-[//]: # (title: Declarations and References)
+
-
+# Declarations and References
+
+Overview of symbol declarations and references.
> This API is available starting from 2020.3 and is currently in development and thus in an experimental state.
>
diff --git a/topics/reference_guide/custom_language_support/parameter_info.md b/topics/reference_guide/custom_language_support/parameter_info.md
index 952e36e1d..34dd19597 100644
--- a/topics/reference_guide/custom_language_support/parameter_info.md
+++ b/topics/reference_guide/custom_language_support/parameter_info.md
@@ -1,6 +1,9 @@
-[//]: # (title: Parameter Info)
+
+
+# Parameter Info
+
+Implementing parameter info handler allowing to display method/function parameter names and types before providing actual values.
-
**Product Help:** [Parameter info](https://www.jetbrains.com/help/idea/viewing-reference-information.html#view-parameter-info)
diff --git a/topics/reference_guide/custom_language_support/registering_file_type.md b/topics/reference_guide/custom_language_support/registering_file_type.md
index 0e98f4be0..abdb88467 100644
--- a/topics/reference_guide/custom_language_support/registering_file_type.md
+++ b/topics/reference_guide/custom_language_support/registering_file_type.md
@@ -1,6 +1,8 @@
-[//]: # (title: Registering a File Type)
+
-
+# Registering a File Type
+
+Registering a language file type associating file extensions and patterns with a language.
diff --git a/topics/reference_guide/frameworks_and_external_apis/xml_dom_api.md b/topics/reference_guide/frameworks_and_external_apis/xml_dom_api.md
index 9607c631e..f76b47ddf 100644
--- a/topics/reference_guide/frameworks_and_external_apis/xml_dom_api.md
+++ b/topics/reference_guide/frameworks_and_external_apis/xml_dom_api.md
@@ -1,9 +1,10 @@
-[//]: # (title: XML DOM API)
+
-
+# XML DOM API
-
+Implementing APIs for accessing XML models.
+[//]: # (TODO content: DOM <=> PSI, Go To Symbol, editor gutter icon->DOM)
This article is intended for plugin writers who create custom web server integrations, or some UI for easy XML editing.
It describes the *Document Object Model* (DOM) in IntelliJ Platform - an easy way to work with DTD or Schema-based XML models.
diff --git a/topics/tutorials/writing_tests_for_plugins/annotator_test.md b/topics/tutorials/writing_tests_for_plugins/annotator_test.md
index 0c722cc47..b74e85cf8 100644
--- a/topics/tutorials/writing_tests_for_plugins/annotator_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/annotator_test.md
@@ -1,6 +1,8 @@
+
+
# 4. Annotator Test
-
+Implementing and running tests for the annotator implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/tutorials/writing_tests_for_plugins/commenter_test.md b/topics/tutorials/writing_tests_for_plugins/commenter_test.md
index 7339c938b..09d833396 100644
--- a/topics/tutorials/writing_tests_for_plugins/commenter_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/commenter_test.md
@@ -1,6 +1,8 @@
+
+
# 9. Commenter Test
-
+Implementing and running test for the commenter implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/tutorials/writing_tests_for_plugins/documentation_test.md b/topics/tutorials/writing_tests_for_plugins/documentation_test.md
index 8507a9ebd..8ccfa520f 100644
--- a/topics/tutorials/writing_tests_for_plugins/documentation_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/documentation_test.md
@@ -1,6 +1,8 @@
+
+
# 11. Documentation Test
-
+Implementing and running test for documentation provider implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/tutorials/writing_tests_for_plugins/find_usages_test.md b/topics/tutorials/writing_tests_for_plugins/find_usages_test.md
index adaad1eba..034d408b5 100644
--- a/topics/tutorials/writing_tests_for_plugins/find_usages_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/find_usages_test.md
@@ -1,6 +1,8 @@
+
+
# 8. Find Usages Test
-
+Implementing and running test for finding usages functionality implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/tutorials/writing_tests_for_plugins/folding_test.md b/topics/tutorials/writing_tests_for_plugins/folding_test.md
index a89fc2748..04aceba18 100644
--- a/topics/tutorials/writing_tests_for_plugins/folding_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/folding_test.md
@@ -1,6 +1,8 @@
+
+
# 7. Folding Test
-
+Implementing and running test for folding builder implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/tutorials/writing_tests_for_plugins/formatter_test.md b/topics/tutorials/writing_tests_for_plugins/formatter_test.md
index 79b092ee5..de1e8d03c 100644
--- a/topics/tutorials/writing_tests_for_plugins/formatter_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/formatter_test.md
@@ -1,6 +1,8 @@
+
+
# 5. Formatter Test
-
+Implementing and running test for the formatter implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/tutorials/writing_tests_for_plugins/reference_test.md b/topics/tutorials/writing_tests_for_plugins/reference_test.md
index 369094310..fc2737717 100644
--- a/topics/tutorials/writing_tests_for_plugins/reference_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/reference_test.md
@@ -1,6 +1,8 @@
+
+
# 10. Reference Test
-
+Implementing and running tests for resolving elements implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/tutorials/writing_tests_for_plugins/rename_test.md b/topics/tutorials/writing_tests_for_plugins/rename_test.md
index e08ea01c8..1b5773fce 100644
--- a/topics/tutorials/writing_tests_for_plugins/rename_test.md
+++ b/topics/tutorials/writing_tests_for_plugins/rename_test.md
@@ -1,6 +1,8 @@
+
+
# 6. Rename Test
-
+Implementing and running test for rename functionality implemented as a part of the Custom Language Support Tutorial.
diff --git a/topics/user_interface_components/notifications.md b/topics/user_interface_components/notifications.md
index ed0e3ce5f..67bc4368e 100644
--- a/topics/user_interface_components/notifications.md
+++ b/topics/user_interface_components/notifications.md
@@ -1,6 +1,8 @@
+
+
# Notifications
-
+Notifying users about errors, action statuses or other events without interrupting their workflow by showing modal message boxes requiring confirmation.