diff --git a/topics/basics/indexing_and_psi_stubs.md b/topics/basics/indexing_and_psi_stubs.md
index 9aa028703..8e1480600 100644
--- a/topics/basics/indexing_and_psi_stubs.md
+++ b/topics/basics/indexing_and_psi_stubs.md
@@ -9,8 +9,8 @@ Plugin developers can use the existing indexes built by the IDE itself and build
 
 It supports two main types of indexes:
 
-* [File-based indexes](file_based_indexes.md)
-* [Stub indexes](stub_indexes.md)
+* [](file_based_indexes.md)
+* [](stub_indexes.md)
 
 File-based indexes are built directly over the content of files.
 Stub indexes are built over serialized *stub trees*.
@@ -18,16 +18,16 @@ A stub tree for a source file is a subset of its PSI tree, which contains only e
 
 Querying a file-based index gets you the set of files matching a specific condition.
 Querying a stub index gets you the set of matching PSI elements.
-Therefore, custom language plugin developers should typically use stub indexes in their plugin implementations.
+Therefore, custom language plugin developers typically use stub indexes in their plugin implementations.
 
-> [Index Viewer](https://plugins.jetbrains.com/plugin/13029-index-viewer/) is a plugin that helps to inspect indexes' contents and properties.
+> [Index Viewer](https://plugins.jetbrains.com/plugin/13029-index-viewer/) plugin can be used to inspect indexes' contents and properties.
 >
 {type="tip"}
 
 ## Dumb Mode
 
 Indexing is a potentially lengthy process.
-It's performed in the background, and during this time, IDE's features are restricted to the ones that don't require index: basic text editing, version control, etc.
+It's performed in the background, and during this time, IDE features are restricted to the ones that don't require index: basic text editing, version control, etc.
 This restriction is managed by [`DumbService`](upsource:///platform/core-api/src/com/intellij/openapi/project/DumbService.java).
 Violations are reported via [`IndexNotReadyException`](upsource:///platform/core-api/src/com/intellij/openapi/project/IndexNotReadyException.java), please see its javadoc on how to adapt callers.
 
@@ -39,26 +39,29 @@ Please see its JavaDoc for more details.
 
 Sometimes, the following conditions hold:
 
-* the aggregation functionality of file-based indexes is not needed.
+* The aggregation functionality of file-based indexes is not needed.
   One just needs to calculate some data based on a particular file's contents and cache it on disk.
-* eagerly calculating the data for the entire project during indexing isn't needed (e.g., it slows down the indexing, and/or this data probably will ever be required for a minor subset of all project files).
-* the data can be recalculated lazily on request without significant performance penalties.
+* Eagerly calculating the data for the entire project during indexing isn't needed (e.g., it slows down the indexing, and/or this data probably will ever be required for a minor subset of all project files).
+* The data can be recalculated lazily on request without significant performance penalties.
 
 A [file-based index](file_based_indexes.md) can be used in such cases, but file gists provide a way to perform data calculation lazily, caching on disk, and a more lightweight API.
 Please see [`VirtualFileGist`](upsource:///platform/indexing-api/src/com/intellij/util/gist/VirtualFileGist.java) and [`PsiFileGist`](upsource:///platform/indexing-api/src/com/intellij/util/gist/PsiFileGist.java) documentation.
 
 **Example:**
-- [`ImageInfoIndex`](upsource:///images/src/org/intellij/images/index/ImageInfoIndex.java) calculating image dimensions/bit depth needed to be displayed in specific parts of UI.
+
+- `VirtualFileGist`: [`ImageInfoIndex`](upsource:///images/src/org/intellij/images/index/ImageInfoIndex.java) calculating image dimensions/bit depth needed to be displayed in specific parts of UI.
+- `PsiFileGist`: [`JavaSimplePropertyGist`](upsource:///java/java-indexing-impl/src/com/intellij/psi/impl/JavaSimplePropertyGist.kt) providing simple properties in Java
 
 ## Improving Indexing Performance
 
 ### Performance Metrics
+
 Indexing performance metrics in JSON format are generated in [logs directory](https://intellij-support.jetbrains.com/hc/en-us/articles/206544519-Directories-used-by-the-IDE-to-store-settings-caches-plugins-and-logs) (see [sandbox directory](ide_development_instance.md#the-development-instance-sandbox-directory) for development instance) in 2020.2 and later.
 These are additionally available in HTML format starting with 2021.1.
 
 ### Avoid Using AST
 
-Use lexer information instead of parsed trees if possible.
+Use [lexer](implementing_lexer.md) information instead of parsed trees if possible.
 
 If impossible, use light AST which doesn't create memory-hungry AST nodes inside, so traversing it might be faster.
 Make sure to traverse only the nodes you need to.
@@ -73,4 +76,4 @@ If a custom language contains lazy-parseable elements that never or rarely conta
 ### Consider Prebuilt Stubs
 
 If your language has a massive standard library, which is mostly the same for all users, you can avoid stub-indexing it in each installation by providing prebuilt stubs with your distribution.
-See [`PrebuiltStubsProvider`](upsource:///platform/indexing-impl/src/com/intellij/psi/stubs/PrebuiltStubs.kt) extension. <!-- PrebuildStubsProvider is deprecated; someone with more expertise in this should rewrite this piece. -->
+See [`PrebuiltStubsProvider`](upsource:///platform/indexing-impl/src/com/intellij/psi/stubs/PrebuiltStubs.kt) extension.