diff --git a/platform/analysis-api/src/com/intellij/codeInsight/completion/CompletionProcess.java b/platform/analysis-api/src/com/intellij/codeInsight/completion/CompletionProcess.java
index 56f667224449..fcea51c9e8e6 100644
--- a/platform/analysis-api/src/com/intellij/codeInsight/completion/CompletionProcess.java
+++ b/platform/analysis-api/src/com/intellij/codeInsight/completion/CompletionProcess.java
@@ -1,6 +1,16 @@
 // Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.codeInsight.completion;
 
+/**
+ * Represents a completion process from the point of view of the completion framework.
+ * It is started when the user types in the editor or invokes completion explicitly (e.g., by a shortcut).
+ * It ends when the completion is finished successfully or canceled.
+ *
+ * @see CompletionService#getCurrentCompletion
+ */
 public interface CompletionProcess {
+  /**
+   * @return {@code true} if completion is triggered by typing in the editor, {@code false} if it's invoked by explicit action (e.g., by a shortcut)
+   */
   boolean isAutopopupCompletion();
 }
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionPhase.kt b/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionPhase.kt
index fbb2d7be495b..01b92dc2dc1b 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionPhase.kt
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionPhase.kt
@@ -60,6 +60,8 @@ import kotlin.math.max
  *  *  [EmptyAutoPopup] -  completion was triggered by typing, but no completion items were found, and the lookup is not shown
  *  *  [InsertedSingleItem] - a single item was found, and it was inserted into the document
  *  *  [NoSuggestionsHint] - candidate inference has finished, but no candidates were found and a warning "no suggestions found" is shown.
+ *
+ *  @See CompletionServiceImpl.completionPhase
  */
 sealed class CompletionPhase @ApiStatus.Internal constructor(
   @JvmField
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java b/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java
index 35be029674f0..dcc2f8a7493e 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java
@@ -81,6 +81,9 @@ import static com.intellij.codeInsight.completion.CompletionPhase.CUSTOM_CODE_CO
 
 /**
  * See cancellation logic in {@link CompletionPhase.BgCalculation#restartOnWriteAction)}
+ *
+ * @see CompletionService#getCurrentCompletion
+ * @see CompletionServiceImpl#getCurrentCompletionProgressIndicator()
  */
 @ApiStatus.Internal
 public final class CompletionProgressIndicator extends ProgressIndicatorBase implements CompletionProcessEx, Disposable {