From cb21247c48c8b0452d9675914e1fcf74482ae672 Mon Sep 17 00:00:00 2001
From: Daniil Ovchinnikov <daniil.ovchinnikov@jetbrains.com>
Date: Thu, 12 Aug 2021 16:01:24 +0200
Subject: [PATCH] [i18n] annotate documentation-related EP implementations

GitOrigin-RevId: 6c7902de7362d28fe8b96a68b49116396fbcb702
---
 .../regexp/RegExpDocumentationProvider.java   |  4 ++--
 .../fileTypes/ImageDocumentationProvider.java |  5 +++--
 .../lang/java/JavaDocumentationProvider.java  | 10 ++++-----
 .../impl/JsonSchemaDocumentationProvider.java |  7 ++++---
 .../CompositeDocumentationProvider.java       |  6 +++---
 .../LiveTemplateDocumentationProvider.java    |  5 +++--
 ...ctionDescriptionDocumentationProvider.java |  5 +++--
 .../WebReferenceDocumentationProvider.java    | 19 +++--------------
 ...alSearchTemplateDocumentationProvider.java |  5 +++--
 .../ant/doc/AntDomDocumentationProvider.java  |  7 ++++---
 .../ExtensionPointDocumentationProvider.java  |  6 +++---
 .../ThemeJsonDocumentationProvider.java       |  6 +++---
 .../EditorConfigDocumentationProvider.kt      |  7 ++++---
 .../GradleDocumentationProvider.java          |  7 ++++---
 .../GroovyDocumentationProvider.java          | 12 +++++------
 .../idea/KotlinDocumentationProvider.kt       |  3 +++
 .../idea/KotlinDocumentationProviderCompat.kt |  3 ++-
 .../dom/MavenModelDocumentationProvider.java  |  7 ++++---
 ...MavenPluginModelDocumentationProvider.java |  7 ++++---
 .../dom/MavenPomXmlDocumentationProvider.java |  7 ++++---
 .../PropertiesDocumentationProvider.java      | 21 ++++---------------
 .../intellij/sh/ShDocumentationProvider.java  |  5 +++--
 .../tasks/doc/TaskDocumentationProvider.java  | 21 ++++---------------
 .../xslt/impl/XsltDocumentationProvider.java  |  3 ++-
 .../impl/YamlDocumentationProviderBase.java   |  5 +++--
 .../YamlJsonSchemaDocumentationProvider.java  |  7 ++++---
 .../PythonDocumentationProvider.java          |  5 +++--
 .../CommandLineDocumentationProvider.java     | 19 +++--------------
 .../console/PydevDocumentationProvider.java   |  5 +++--
 .../PythonExternalDocumentationProvider.java  |  5 +++--
 .../util/xml/DomDocumentationProvider.java    |  5 +++--
 .../HtmlDocumentationProvider.java            |  7 ++++---
 .../XmlDocumentationProvider.java             |  7 ++++---
 .../relaxNG/RngDocumentationProvider.java     |  3 ++-
 .../relaxNG/compact/RngCompactLanguage.java   |  3 ++-
 .../mdn/XmlMdnDocumentationProvider.kt        |  5 +++--
 36 files changed, 120 insertions(+), 144 deletions(-)

diff --git a/RegExpSupport/src/org/intellij/lang/regexp/RegExpDocumentationProvider.java b/RegExpSupport/src/org/intellij/lang/regexp/RegExpDocumentationProvider.java
index 37b0eeea7561..6d3396557d50 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/RegExpDocumentationProvider.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/RegExpDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2020 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.intellij.lang.regexp;
 
 import com.intellij.lang.ASTNode;
@@ -37,7 +37,7 @@ public final class RegExpDocumentationProvider extends AbstractDocumentationProv
 
   @Override
   @Nullable
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (element instanceof RegExpGroup) {
       final RegExpGroup group = (RegExpGroup)element;
       return StringUtil.escapeXmlEntities(group.getUnescapedText());
diff --git a/images/src/org/intellij/images/fileTypes/ImageDocumentationProvider.java b/images/src/org/intellij/images/fileTypes/ImageDocumentationProvider.java
index 424b84ba02eb..8403f68f693b 100644
--- a/images/src/org/intellij/images/fileTypes/ImageDocumentationProvider.java
+++ b/images/src/org/intellij/images/fileTypes/ImageDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.intellij.images.fileTypes;
 
 import com.intellij.lang.documentation.AbstractDocumentationProvider;
@@ -10,6 +10,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFileSystemItem;
 import org.intellij.images.index.ImageInfoIndex;
 import org.intellij.images.util.ImageInfo;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.Nullable;
 
 import java.net.URI;
@@ -22,7 +23,7 @@ public class ImageDocumentationProvider extends AbstractDocumentationProvider {
   private static final int MAX_IMAGE_SIZE = 300;
 
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     final Ref<String> result = Ref.create();
 
     if (element instanceof PsiFileSystemItem && !((PsiFileSystemItem)element).isDirectory()) {
diff --git a/java/java-impl/src/com/intellij/lang/java/JavaDocumentationProvider.java b/java/java-impl/src/com/intellij/lang/java/JavaDocumentationProvider.java
index a369b57311d4..b7763fab4c44 100644
--- a/java/java-impl/src/com/intellij/lang/java/JavaDocumentationProvider.java
+++ b/java/java-impl/src/com/intellij/lang/java/JavaDocumentationProvider.java
@@ -76,7 +76,7 @@ public class JavaDocumentationProvider implements CodeDocumentationProvider, Ext
   public static final String PACKAGE_SUMMARY_FILE = "package-summary.html";
 
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     return QuickDocUtil.inferLinkFromFullDocumentation(this, element, originalElement,
                                                        getQuickNavigationInfoInner(element, originalElement));
   }
@@ -508,7 +508,7 @@ public class JavaDocumentationProvider implements CodeDocumentationProvider, Ext
   }
 
   @Override
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     // for new Class(<caret>) or methodCall(<caret>) proceed from method call or new expression
     // same for new Cl<caret>ass() or method<caret>Call()
     if (element instanceof PsiExpressionList ||
@@ -576,7 +576,7 @@ public class JavaDocumentationProvider implements CodeDocumentationProvider, Ext
   }
 
   @Override
-  public @Nullable String generateHoverDoc(@NotNull PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls @Nullable String generateHoverDoc(@NotNull PsiElement element, @Nullable PsiElement originalElement) {
     if (originalElement != null && PsiTreeUtil.isAncestor(element, originalElement, false)) {
       return null;
     }
@@ -584,7 +584,7 @@ public class JavaDocumentationProvider implements CodeDocumentationProvider, Ext
   }
 
   @Override
-  public @Nullable String generateRenderedDoc(@NotNull PsiDocCommentBase comment) {
+  public @Nls @Nullable String generateRenderedDoc(@NotNull PsiDocCommentBase comment) {
     PsiElement target = comment.getOwner();
     if (target == null) target = comment;
     JavaDocInfoGenerator generator = JavaDocInfoGeneratorFactory.create(target.getProject(), target);
@@ -890,7 +890,7 @@ public class JavaDocumentationProvider implements CodeDocumentationProvider, Ext
   }
 
   @Override
-  public String fetchExternalDocumentation(Project project, PsiElement element, List<String> docUrls, boolean onHover) {
+  public @Nls String fetchExternalDocumentation(Project project, PsiElement element, List<String> docUrls, boolean onHover) {
     return fetchExternalJavadoc(element, project, docUrls);
   }
 
diff --git a/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaDocumentationProvider.java b/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaDocumentationProvider.java
index 36b066e6582b..a6d9657b9bcf 100644
--- a/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaDocumentationProvider.java
+++ b/json/src/com/jetbrains/jsonSchema/impl/JsonSchemaDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2020 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.jetbrains.jsonSchema.impl;
 
 import com.intellij.json.JsonBundle;
@@ -17,6 +17,7 @@ import com.intellij.util.ObjectUtils;
 import com.jetbrains.jsonSchema.extension.JsonLikePsiWalker;
 import com.jetbrains.jsonSchema.extension.JsonSchemaFileProvider;
 import com.jetbrains.jsonSchema.ide.JsonSchemaService;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -28,13 +29,13 @@ import java.util.List;
 public class JsonSchemaDocumentationProvider implements DocumentationProvider {
   @Nullable
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     return findSchemaAndGenerateDoc(element, originalElement, true, null);
   }
 
   @Nullable
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     String forcedPropName = null;
     if (element instanceof FakeDocElement) {
       forcedPropName = ((FakeDocElement)element).myAltName;
diff --git a/platform/analysis-api/src/com/intellij/lang/documentation/CompositeDocumentationProvider.java b/platform/analysis-api/src/com/intellij/lang/documentation/CompositeDocumentationProvider.java
index 278e26daca0f..6e8cc5188a58 100644
--- a/platform/analysis-api/src/com/intellij/lang/documentation/CompositeDocumentationProvider.java
+++ b/platform/analysis-api/src/com/intellij/lang/documentation/CompositeDocumentationProvider.java
@@ -111,7 +111,7 @@ public final class CompositeDocumentationProvider implements DocumentationProvid
   }
 
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     for (DocumentationProvider provider : getAllProviders()) {
       String result = provider.getQuickNavigateInfo(element, originalElement);
       if (result != null) {
@@ -135,7 +135,7 @@ public final class CompositeDocumentationProvider implements DocumentationProvid
   }
 
   @Override
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     for (DocumentationProvider provider : getAllProviders()) {
       String result = provider.generateDoc(element, originalElement);
       if (result != null) {
@@ -159,7 +159,7 @@ public final class CompositeDocumentationProvider implements DocumentationProvid
   }
 
   @Override
-  public @Nullable String generateRenderedDoc(@NotNull PsiDocCommentBase comment) {
+  public @Nls @Nullable String generateRenderedDoc(@NotNull PsiDocCommentBase comment) {
     for (DocumentationProvider provider : getAllProviders()) {
       String result = provider.generateRenderedDoc(comment);
       if (result != null) {
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/template/impl/LiveTemplateDocumentationProvider.java b/platform/lang-impl/src/com/intellij/codeInsight/template/impl/LiveTemplateDocumentationProvider.java
index 4533bd8b05e9..81baf3151f6b 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/template/impl/LiveTemplateDocumentationProvider.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/template/impl/LiveTemplateDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. 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.template.impl;
 
 import com.intellij.lang.documentation.AbstractDocumentationProvider;
@@ -10,6 +10,7 @@ import com.intellij.psi.PsiManager;
 import com.intellij.psi.impl.FakePsiElement;
 import com.intellij.psi.impl.source.DummyHolder;
 import com.intellij.psi.impl.source.DummyHolderFactory;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -29,7 +30,7 @@ public class LiveTemplateDocumentationProvider extends AbstractDocumentationProv
   }
 
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     if (!(element instanceof LiveTemplateElement)) {
       return null;
     }
diff --git a/platform/lang-impl/src/com/intellij/codeInspection/actions/InspectionDescriptionDocumentationProvider.java b/platform/lang-impl/src/com/intellij/codeInspection/actions/InspectionDescriptionDocumentationProvider.java
index 6fecf3e867b7..78c79fa5195b 100644
--- a/platform/lang-impl/src/com/intellij/codeInspection/actions/InspectionDescriptionDocumentationProvider.java
+++ b/platform/lang-impl/src/com/intellij/codeInspection/actions/InspectionDescriptionDocumentationProvider.java
@@ -1,5 +1,5 @@
 
-// Copyright 2000-2018 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.codeInspection.actions;
 
 import com.intellij.codeInspection.ex.InspectionToolWrapper;
@@ -8,11 +8,12 @@ import com.intellij.lang.documentation.AbstractDocumentationProvider;
 import com.intellij.lang.documentation.DocumentationMarkup;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.Nullable;
 
 public class InspectionDescriptionDocumentationProvider extends AbstractDocumentationProvider {
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     if (!(element instanceof InspectionElement)) {
       return null;
     }
diff --git a/platform/lang-impl/src/com/intellij/openapi/paths/WebReferenceDocumentationProvider.java b/platform/lang-impl/src/com/intellij/openapi/paths/WebReferenceDocumentationProvider.java
index 86aa9258acb0..45614401c2d2 100644
--- a/platform/lang-impl/src/com/intellij/openapi/paths/WebReferenceDocumentationProvider.java
+++ b/platform/lang-impl/src/com/intellij/openapi/paths/WebReferenceDocumentationProvider.java
@@ -1,30 +1,17 @@
-/*
- * Copyright 2000-2011 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.openapi.paths;
 
 import com.intellij.ide.IdeBundle;
 import com.intellij.lang.documentation.AbstractDocumentationProvider;
 import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.Nls;
 
 /**
  * @author Eugene.Kudelevsky
  */
 public class WebReferenceDocumentationProvider extends AbstractDocumentationProvider {
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (element instanceof WebReference.MyFakePsiElement) {
       return IdeBundle.message("open.url.in.browser.tooltip");
     }
diff --git a/platform/structuralsearch/source/com/intellij/structuralsearch/plugin/ui/StructuralSearchTemplateDocumentationProvider.java b/platform/structuralsearch/source/com/intellij/structuralsearch/plugin/ui/StructuralSearchTemplateDocumentationProvider.java
index bb19f34550e8..d6e5699f338d 100644
--- a/platform/structuralsearch/source/com/intellij/structuralsearch/plugin/ui/StructuralSearchTemplateDocumentationProvider.java
+++ b/platform/structuralsearch/source/com/intellij/structuralsearch/plugin/ui/StructuralSearchTemplateDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.structuralsearch.plugin.ui;
 
 import com.intellij.lang.documentation.AbstractDocumentationProvider;
@@ -10,6 +10,7 @@ import com.intellij.psi.PsiManager;
 import com.intellij.psi.impl.FakePsiElement;
 import com.intellij.psi.impl.source.DummyHolder;
 import com.intellij.psi.impl.source.DummyHolderFactory;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -25,7 +26,7 @@ public class StructuralSearchTemplateDocumentationProvider extends AbstractDocum
   }
 
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     if (!(element instanceof ConfigurationElement)) {
       return null;
     }
diff --git a/plugins/ant/src/com/intellij/lang/ant/doc/AntDomDocumentationProvider.java b/plugins/ant/src/com/intellij/lang/ant/doc/AntDomDocumentationProvider.java
index 1047a8ab6b78..4d47004f7d30 100644
--- a/plugins/ant/src/com/intellij/lang/ant/doc/AntDomDocumentationProvider.java
+++ b/plugins/ant/src/com/intellij/lang/ant/doc/AntDomDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.lang.ant.doc;
 
 import com.intellij.lang.ant.AntFilesProvider;
@@ -21,6 +21,7 @@ import com.intellij.psi.xml.XmlTag;
 import com.intellij.util.xml.DomElement;
 import com.intellij.util.xml.DomTarget;
 import com.intellij.util.xml.reflect.DomChildrenDescription;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.Nullable;
 
@@ -36,7 +37,7 @@ public class AntDomDocumentationProvider implements DocumentationProvider {
   private static final Logger LOG = Logger.getInstance(AntDomDocumentationProvider.class);
 
   @Override
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     final String mainDoc = getMainDocumentation(originalElement);
     final String additionalDoc = getAdditionalDocumentation(originalElement);
     if (mainDoc == null && additionalDoc == null) {
@@ -172,7 +173,7 @@ public class AntDomDocumentationProvider implements DocumentationProvider {
 
   @Override
   @Nullable
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {  // todo!
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {  // todo!
     if (element instanceof PomTargetPsiElement) {
       final PomTarget pomTarget = ((PomTargetPsiElement)element).getTarget();
       if (pomTarget instanceof DomTarget) {
diff --git a/plugins/devkit/devkit-core/src/references/extensions/ExtensionPointDocumentationProvider.java b/plugins/devkit/devkit-core/src/references/extensions/ExtensionPointDocumentationProvider.java
index 4ab7493101a4..65f67948c2ca 100644
--- a/plugins/devkit/devkit-core/src/references/extensions/ExtensionPointDocumentationProvider.java
+++ b/plugins/devkit/devkit-core/src/references/extensions/ExtensionPointDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.idea.devkit.references.extensions;
 
 import com.intellij.codeInsight.documentation.DocumentationManager;
@@ -27,7 +27,7 @@ import org.jetbrains.idea.devkit.util.DescriptorUtil;
 public class ExtensionPointDocumentationProvider implements DocumentationProvider {
 
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     ExtensionPoint extensionPoint = findExtensionPoint(element);
     if (extensionPoint == null) return null;
 
@@ -56,7 +56,7 @@ public class ExtensionPointDocumentationProvider implements DocumentationProvide
   }
 
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     ExtensionPoint extensionPoint = findExtensionPoint(element);
     if (extensionPoint == null) return null;
 
diff --git a/plugins/devkit/devkit-core/src/themes/ThemeJsonDocumentationProvider.java b/plugins/devkit/devkit-core/src/themes/ThemeJsonDocumentationProvider.java
index 80eb64cb97d2..4742b2b5085f 100644
--- a/plugins/devkit/devkit-core/src/themes/ThemeJsonDocumentationProvider.java
+++ b/plugins/devkit/devkit-core/src/themes/ThemeJsonDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.idea.devkit.themes;
 
 import com.intellij.codeInsight.javadoc.JavaDocInfoGenerator;
@@ -25,7 +25,7 @@ public class ThemeJsonDocumentationProvider extends AbstractDocumentationProvide
 
   @Nullable
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     final Pair<UIThemeMetadata, UIThemeMetadata.UIKeyMetadata> resolve = resolve(element);
     if (resolve == null) return null;
 
@@ -39,7 +39,7 @@ public class ThemeJsonDocumentationProvider extends AbstractDocumentationProvide
   }
 
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     final Pair<UIThemeMetadata, UIThemeMetadata.UIKeyMetadata> resolve = resolve(element);
     if (resolve == null) return null;
 
diff --git a/plugins/editorconfig/src/org/editorconfig/language/codeinsight/documentation/EditorConfigDocumentationProvider.kt b/plugins/editorconfig/src/org/editorconfig/language/codeinsight/documentation/EditorConfigDocumentationProvider.kt
index 9cc7cd100356..a29deac0ed10 100644
--- a/plugins/editorconfig/src/org/editorconfig/language/codeinsight/documentation/EditorConfigDocumentationProvider.kt
+++ b/plugins/editorconfig/src/org/editorconfig/language/codeinsight/documentation/EditorConfigDocumentationProvider.kt
@@ -1,4 +1,4 @@
-// Copyright 2000-2018 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.editorconfig.language.codeinsight.documentation
 
 import com.intellij.lang.documentation.DocumentationProvider
@@ -10,15 +10,16 @@ import com.intellij.psi.PsiWhiteSpace
 import org.editorconfig.language.psi.interfaces.EditorConfigDescribableElement
 import org.editorconfig.language.schema.descriptors.EditorConfigDescriptor
 import org.editorconfig.language.util.EditorConfigPsiTreeUtil.getParentOfType
+import org.jetbrains.annotations.Nls
 import kotlin.math.max
 
 class EditorConfigDocumentationProvider : DocumentationProvider {
-  override fun generateDoc(element: PsiElement, originalElement: PsiElement?): String? {
+  override fun generateDoc(element: PsiElement, originalElement: PsiElement?): @Nls String? {
     element as? EditorConfigDocumentationHolderElement ?: return null
     return element.descriptor?.documentation
   }
 
-  override fun getQuickNavigateInfo(element: PsiElement, originalElement: PsiElement?): String? {
+  override fun getQuickNavigateInfo(element: PsiElement, originalElement: PsiElement?): @Nls String? {
     element as? EditorConfigDocumentationHolderElement ?: return null
     return element.descriptor?.documentation
   }
diff --git a/plugins/gradle/java/src/documentation/GradleDocumentationProvider.java b/plugins/gradle/java/src/documentation/GradleDocumentationProvider.java
index ca90684d5f1a..f3ac7bc2ef76 100644
--- a/plugins/gradle/java/src/documentation/GradleDocumentationProvider.java
+++ b/plugins/gradle/java/src/documentation/GradleDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.plugins.gradle.documentation;
 
 import com.intellij.codeInsight.javadoc.JavaDocUtil;
@@ -10,6 +10,7 @@ import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiManager;
 import com.intellij.psi.PsiMethod;
 import com.intellij.psi.util.PsiTreeUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.plugins.gradle.util.GradleConstants;
 import org.jetbrains.plugins.gradle.util.GradleDocumentationBundle;
@@ -27,7 +28,7 @@ public class GradleDocumentationProvider implements DocumentationProvider {
 
   @Nullable
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     PsiFile file = element.getContainingFile();
     if (file == null || !FileUtilRt.extensionEquals(file.getName(), GradleConstants.EXTENSION)) return null;
     if (element instanceof GrLightVariable) {
@@ -42,7 +43,7 @@ public class GradleDocumentationProvider implements DocumentationProvider {
 
   @Nullable
   @Override
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     PsiFile file = element.getContainingFile();
     if (file == null || !FileUtilRt.extensionEquals(file.getName(), GradleConstants.EXTENSION)) return null;
     return element instanceof GrLiteral ? findDoc(element, ((GrLiteral)element).getValue()) : null;
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/documentation/GroovyDocumentationProvider.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/documentation/GroovyDocumentationProvider.java
index 2f21baf452e8..29cc8af0828a 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/documentation/GroovyDocumentationProvider.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/documentation/GroovyDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.plugins.groovy.lang.documentation;
 
 import com.intellij.codeInsight.CodeInsightBundle;
@@ -14,7 +14,6 @@ import com.intellij.lang.documentation.CompositeDocumentationProvider;
 import com.intellij.lang.documentation.ExternalDocumentationProvider;
 import com.intellij.lang.java.JavaDocumentationProvider;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.util.NlsSafe;
 import com.intellij.openapi.util.Pair;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
@@ -22,6 +21,7 @@ import com.intellij.psi.util.PsiFormatUtil;
 import com.intellij.psi.util.PsiFormatUtilBase;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -75,7 +75,7 @@ public class GroovyDocumentationProvider implements CodeDocumentationProvider, E
 
   @Override
   @Nullable
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (element instanceof GrVariable || element instanceof GrImplicitVariable) {
       StringBuilder buffer = new StringBuilder();
       PsiVariable variable = (PsiVariable)element;
@@ -277,7 +277,7 @@ public class GroovyDocumentationProvider implements CodeDocumentationProvider, E
 
   @Override
   @Nullable
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     if (element instanceof GdslNamedParameter) {
       GdslNamedParameter parameter = (GdslNamedParameter)element;
       String result = "<pre><b>" + parameter.getName() + "</b>";
@@ -380,7 +380,7 @@ public class GroovyDocumentationProvider implements CodeDocumentationProvider, E
   }
 
   @Override
-  public String fetchExternalDocumentation(final Project project, PsiElement element, final List<String> docUrls, boolean onHover) {
+  public @Nls String fetchExternalDocumentation(final Project project, PsiElement element, final List<String> docUrls, boolean onHover) {
     return JavaDocumentationProvider.fetchExternalJavadoc(element, project, docUrls);
   }
 
@@ -540,7 +540,7 @@ public class GroovyDocumentationProvider implements CodeDocumentationProvider, E
   }
 
   @Override
-  public @Nullable @NlsSafe String generateRenderedDoc(@NotNull PsiDocCommentBase comment) {
+  public @Nls @Nullable String generateRenderedDoc(@NotNull PsiDocCommentBase comment) {
     PsiElement owner = comment.getOwner();
     String html = new GroovyDocInfoGenerator(owner == null ? comment : owner).generateRenderedDocInfo();
     return JavaDocExternalFilter.filterInternalDocInfo(html);
diff --git a/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProvider.kt b/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProvider.kt
index feabbf5bbe46..afc8e7256f1b 100644
--- a/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProvider.kt
+++ b/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProvider.kt
@@ -12,6 +12,7 @@ import com.intellij.openapi.diagnostic.Logger
 import com.intellij.openapi.editor.Editor
 import com.intellij.psi.*
 import com.intellij.psi.impl.compiled.ClsMethodImpl
+import org.jetbrains.annotations.Nls
 import org.jetbrains.kotlin.asJava.LightClassUtil
 import org.jetbrains.kotlin.asJava.elements.KtLightDeclaration
 import org.jetbrains.kotlin.descriptors.*
@@ -126,10 +127,12 @@ open class KotlinDocumentationProviderCompatBase : AbstractDocumentationProvider
         return if (contextElement.isModifier()) contextElement else null
     }
 
+    @Nls
     override fun getQuickNavigateInfo(element: PsiElement?, originalElement: PsiElement?): String? {
         return if (element == null) null else getText(element, originalElement, true)
     }
 
+    @Nls
     override fun generateDoc(element: PsiElement, originalElement: PsiElement?): String? {
         return getText(element, originalElement, false)
     }
diff --git a/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProviderCompat.kt b/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProviderCompat.kt
index 06b211f23626..f704ab28e292 100644
--- a/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProviderCompat.kt
+++ b/plugins/kotlin/idea/src/org/jetbrains/kotlin/idea/KotlinDocumentationProviderCompat.kt
@@ -4,9 +4,9 @@ package org.jetbrains.kotlin.idea
 
 import com.intellij.codeInsight.javadoc.JavaDocExternalFilter
 import com.intellij.psi.PsiDocCommentBase
-import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import com.intellij.psi.util.PsiTreeUtil
+import org.jetbrains.annotations.Nls
 import org.jetbrains.kotlin.kdoc.psi.api.KDoc
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtFile
@@ -24,6 +24,7 @@ class KotlinDocumentationProvider : KotlinDocumentationProviderCompatBase() {
         }
     }
 
+    @Nls
     override fun generateRenderedDoc(comment: PsiDocCommentBase): String? {
         val docComment = comment as? KDoc ?: return null
 
diff --git a/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenModelDocumentationProvider.java b/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenModelDocumentationProvider.java
index 2b2140cf96c1..dd52a5012236 100644
--- a/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenModelDocumentationProvider.java
+++ b/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenModelDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.idea.maven.dom;
 
 import com.intellij.lang.documentation.DocumentationProvider;
@@ -13,6 +13,7 @@ import com.intellij.psi.impl.FakePsiElement;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.xml.XmlTag;
 import com.intellij.usageView.UsageViewTypeLocation;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.idea.maven.dom.references.MavenPsiElementWrapper;
@@ -24,7 +25,7 @@ import java.util.List;
 
 public class MavenModelDocumentationProvider implements DocumentationProvider, ElementDescriptionProvider {
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     return getDoc(element, false);
   }
 
@@ -41,7 +42,7 @@ public class MavenModelDocumentationProvider implements DocumentationProvider, E
   }
 
   @Override
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     return getDoc(element, true);
   }
 
diff --git a/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPluginModelDocumentationProvider.java b/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPluginModelDocumentationProvider.java
index f2c59547c9f8..3a3a7ea61425 100644
--- a/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPluginModelDocumentationProvider.java
+++ b/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPluginModelDocumentationProvider.java
@@ -1,17 +1,18 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.idea.maven.dom;
 
 import com.intellij.lang.documentation.DocumentationProvider;
 import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.Nls;
 
 public class MavenPluginModelDocumentationProvider implements DocumentationProvider {
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     return getDocForMavenPluginParameter(element, false);
   }
 
   @Override
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     return getDocForMavenPluginParameter(element, true);
   }
 
diff --git a/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPomXmlDocumentationProvider.java b/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPomXmlDocumentationProvider.java
index ef151a2c785e..26a28ae65695 100644
--- a/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPomXmlDocumentationProvider.java
+++ b/plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/MavenPomXmlDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.idea.maven.dom;
 
 import com.intellij.lang.documentation.DocumentationProvider;
@@ -7,6 +7,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiManager;
 import com.intellij.xml.util.documentation.XmlDocumentationProvider;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
@@ -37,7 +38,7 @@ public class MavenPomXmlDocumentationProvider implements DocumentationProvider {
 
   @Nullable
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (!isFromPomXml(element)) return null;
 
     return myDelegate.getQuickNavigateInfo(element, originalElement);
@@ -53,7 +54,7 @@ public class MavenPomXmlDocumentationProvider implements DocumentationProvider {
 
   @Nullable
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     if (!isFromPomXml(element)) return null;
 
     return myDelegate.generateDoc(element, originalElement);
diff --git a/plugins/properties/src/com/intellij/lang/properties/PropertiesDocumentationProvider.java b/plugins/properties/src/com/intellij/lang/properties/PropertiesDocumentationProvider.java
index ab645fa6f851..f91fabb4127c 100644
--- a/plugins/properties/src/com/intellij/lang/properties/PropertiesDocumentationProvider.java
+++ b/plugins/properties/src/com/intellij/lang/properties/PropertiesDocumentationProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2009 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 
 /*
  * @author max
@@ -27,6 +13,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiFile;
 import com.intellij.ui.GuiUtils;
 import com.intellij.util.containers.ContainerUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -36,7 +23,7 @@ import java.awt.*;
 public class PropertiesDocumentationProvider extends AbstractDocumentationProvider {
   @Override
   @Nullable
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (element instanceof IProperty) {
       return "\"" + renderPropertyValue((IProperty)element) + "\"" + getLocationString(element);
     }
@@ -58,7 +45,7 @@ public class PropertiesDocumentationProvider extends AbstractDocumentationProvid
   }
 
   @Override
-  public String generateDoc(final PsiElement element, @Nullable final PsiElement originalElement) {
+  public @Nls String generateDoc(final PsiElement element, @Nullable final PsiElement originalElement) {
     if (element instanceof IProperty) {
       IProperty property = (IProperty)element;
       String text = property.getDocCommentText();
diff --git a/plugins/sh/src/com/intellij/sh/ShDocumentationProvider.java b/plugins/sh/src/com/intellij/sh/ShDocumentationProvider.java
index 46d4a25fc2fb..69b40c8f23f7 100644
--- a/plugins/sh/src/com/intellij/sh/ShDocumentationProvider.java
+++ b/plugins/sh/src/com/intellij/sh/ShDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.sh;
 
 import com.intellij.execution.configurations.GeneralCommandLine;
@@ -24,6 +24,7 @@ import com.intellij.sh.psi.ShGenericCommandDirective;
 import com.intellij.sh.psi.ShLiteral;
 import com.intellij.util.EnvironmentUtil;
 import com.intellij.util.io.URLUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -54,7 +55,7 @@ final class ShDocumentationProvider implements DocumentationProvider {
   };
 
   @Override
-  public String generateDoc(PsiElement o, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement o, PsiElement originalElement) {
     if (!wordWithDocumentation(o)) return null;
 
     DOCUMENTATION_PROVIDER_USED_EVENT_ID.log();
diff --git a/plugins/tasks/tasks-core/src/com/intellij/tasks/doc/TaskDocumentationProvider.java b/plugins/tasks/tasks-core/src/com/intellij/tasks/doc/TaskDocumentationProvider.java
index 1c29bf35a3a6..d5e20cb68357 100644
--- a/plugins/tasks/tasks-core/src/com/intellij/tasks/doc/TaskDocumentationProvider.java
+++ b/plugins/tasks/tasks-core/src/com/intellij/tasks/doc/TaskDocumentationProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2011 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.tasks.doc;
 
 import com.intellij.lang.documentation.AbstractDocumentationProvider;
@@ -24,6 +10,7 @@ import com.intellij.tasks.Comment;
 import com.intellij.tasks.Task;
 import com.intellij.xml.util.XmlStringUtil;
 import com.petebevin.markdown.MarkdownProcessor;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.Collections;
@@ -46,7 +33,7 @@ public class TaskDocumentationProvider extends AbstractDocumentationProvider imp
   }
 
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     if (!(element instanceof TaskPsiElement)) return null;
     final Task task = ((TaskPsiElement)element).getTask();
     final StringBuilder builder = new StringBuilder();
@@ -76,7 +63,7 @@ public class TaskDocumentationProvider extends AbstractDocumentationProvider imp
 
 
   @Override
-  public String fetchExternalDocumentation(Project project, PsiElement element, List<String> docUrls, boolean onHover) {
+  public @Nls String fetchExternalDocumentation(Project project, PsiElement element, List<String> docUrls, boolean onHover) {
     return null;
   }
 
diff --git a/plugins/xpath/xpath-lang/src/org/intellij/lang/xpath/xslt/impl/XsltDocumentationProvider.java b/plugins/xpath/xpath-lang/src/org/intellij/lang/xpath/xslt/impl/XsltDocumentationProvider.java
index 6dd5d17776d6..c65ff98d53b6 100644
--- a/plugins/xpath/xpath-lang/src/org/intellij/lang/xpath/xslt/impl/XsltDocumentationProvider.java
+++ b/plugins/xpath/xpath-lang/src/org/intellij/lang/xpath/xslt/impl/XsltDocumentationProvider.java
@@ -36,6 +36,7 @@ import org.jdom.JDOMException;
 import org.jdom.input.SAXBuilder;
 import org.jdom.transform.JDOMSource;
 import org.jdom.xpath.XPath;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -96,7 +97,7 @@ public class XsltDocumentationProvider implements DocumentationProvider {
 
     @Override
     @Nullable
-    public String generateDoc(PsiElement psiElement, PsiElement psiElement1) {
+    public @Nls String generateDoc(PsiElement psiElement, PsiElement psiElement1) {
         if (psiElement instanceof DocElement) {
             final DocElement element = (DocElement)psiElement;
             return getDocumentation(element.getName(), element.getCategory());
diff --git a/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlDocumentationProviderBase.java b/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlDocumentationProviderBase.java
index 7a583700bfcc..757b7b3714ea 100644
--- a/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlDocumentationProviderBase.java
+++ b/plugins/yaml/src/org/jetbrains/yaml/meta/impl/YamlDocumentationProviderBase.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.yaml.meta.impl;
 
 import com.intellij.lang.documentation.DocumentationProvider;
@@ -10,6 +10,7 @@ import com.intellij.psi.PsiManager;
 import com.intellij.psi.impl.light.LightElement;
 import com.intellij.psi.util.PsiTreeUtil;
 import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.yaml.YAMLLanguage;
@@ -28,7 +29,7 @@ import java.util.Objects;
 public abstract class YamlDocumentationProviderBase implements DocumentationProvider {
 
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     if (!(element instanceof DocumentationElement)) {
       return null;
     }
diff --git a/plugins/yaml/src/org/jetbrains/yaml/schema/YamlJsonSchemaDocumentationProvider.java b/plugins/yaml/src/org/jetbrains/yaml/schema/YamlJsonSchemaDocumentationProvider.java
index 7432f45e43f8..68e742f7930f 100644
--- a/plugins/yaml/src/org/jetbrains/yaml/schema/YamlJsonSchemaDocumentationProvider.java
+++ b/plugins/yaml/src/org/jetbrains/yaml/schema/YamlJsonSchemaDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.jetbrains.yaml.schema;
 
 import com.intellij.lang.documentation.DocumentationProvider;
@@ -8,19 +8,20 @@ import com.intellij.psi.PsiFile;
 import com.jetbrains.jsonSchema.ide.JsonSchemaService;
 import com.jetbrains.jsonSchema.impl.JsonSchemaDocumentationProvider;
 import com.jetbrains.jsonSchema.impl.JsonSchemaObject;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class YamlJsonSchemaDocumentationProvider implements DocumentationProvider {
   @Nullable
   @Override
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     return findSchemaAndGenerateDoc(element, true);
   }
 
   @Nullable
   @Override
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     return findSchemaAndGenerateDoc(element, false);
   }
 
diff --git a/python/python-psi-impl/src/com/jetbrains/python/documentation/PythonDocumentationProvider.java b/python/python-psi-impl/src/com/jetbrains/python/documentation/PythonDocumentationProvider.java
index 42a6ca7f440d..89ff1e03dec1 100644
--- a/python/python-psi-impl/src/com/jetbrains/python/documentation/PythonDocumentationProvider.java
+++ b/python/python-psi-impl/src/com/jetbrains/python/documentation/PythonDocumentationProvider.java
@@ -29,6 +29,7 @@ import com.jetbrains.python.psi.resolve.QualifiedNameFinder;
 import com.jetbrains.python.psi.types.*;
 import com.jetbrains.python.toolbox.ChainIterable;
 import one.util.streamex.StreamEx;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -54,7 +55,7 @@ public class PythonDocumentationProvider implements DocumentationProvider {
   // provides ctrl+hover info
   @Override
   @Nullable
-  public String getQuickNavigateInfo(PsiElement element, @NotNull PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, @NotNull PsiElement originalElement) {
     for (PythonDocumentationQuickInfoProvider point : PythonDocumentationQuickInfoProvider.EP_NAME.getExtensions()) {
       final String info = point.getQuickInfo(originalElement);
       if (info != null) {
@@ -490,7 +491,7 @@ public class PythonDocumentationProvider implements DocumentationProvider {
 
   // provides ctrl+Q doc
   @Override
-  public String generateDoc(@NotNull PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(@NotNull PsiElement element, @Nullable PsiElement originalElement) {
     final PythonRuntimeService runtimeService = PythonRuntimeService.getInstance();
     if (runtimeService.isInPydevConsole(element) || originalElement != null && runtimeService.isInPydevConsole(originalElement)) {
       return runtimeService.createPydevDoc(element, originalElement);
diff --git a/python/src/com/jetbrains/commandInterface/commandLine/CommandLineDocumentationProvider.java b/python/src/com/jetbrains/commandInterface/commandLine/CommandLineDocumentationProvider.java
index fe26428089c9..2f7f339808dc 100644
--- a/python/src/com/jetbrains/commandInterface/commandLine/CommandLineDocumentationProvider.java
+++ b/python/src/com/jetbrains/commandInterface/commandLine/CommandLineDocumentationProvider.java
@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.jetbrains.commandInterface.commandLine;
 
 import com.intellij.lang.documentation.DocumentationProvider;
@@ -29,6 +15,7 @@ import com.jetbrains.commandInterface.commandLine.psi.CommandLineCommand;
 import com.jetbrains.commandInterface.commandLine.psi.CommandLineOption;
 import com.jetbrains.commandInterface.commandLine.psi.CommandLineVisitor;
 import com.jetbrains.python.psi.PyUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -44,7 +31,7 @@ import java.util.List;
 public final class CommandLineDocumentationProvider implements DocumentationProvider {
   @Nullable
   @Override
-  public String generateDoc(final PsiElement element, @Nullable final PsiElement originalElement) {
+  public @Nls String generateDoc(final PsiElement element, @Nullable final PsiElement originalElement) {
     final Help help = findHelp(element);
     if (help == null) {
       return null;
diff --git a/python/src/com/jetbrains/python/console/PydevDocumentationProvider.java b/python/src/com/jetbrains/python/console/PydevDocumentationProvider.java
index 66de5a100885..702607eabb85 100644
--- a/python/src/com/jetbrains/python/console/PydevDocumentationProvider.java
+++ b/python/src/com/jetbrains/python/console/PydevDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2020 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.jetbrains.python.console;
 
 import com.intellij.lang.documentation.AbstractDocumentationProvider;
@@ -11,6 +11,7 @@ import com.jetbrains.python.documentation.PyDocumentationBuilder;
 import com.jetbrains.python.psi.PyElement;
 import com.jetbrains.python.psi.PyReferenceExpression;
 import com.jetbrains.python.psi.PyUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.Nullable;
 
 public class PydevDocumentationProvider extends AbstractDocumentationProvider {
@@ -24,7 +25,7 @@ public class PydevDocumentationProvider extends AbstractDocumentationProvider {
   }
 
   @Override
-  public String generateDoc(final PsiElement element, @Nullable final PsiElement originalElement) {
+  public @Nls String generateDoc(final PsiElement element, @Nullable final PsiElement originalElement) {
     // Process PydevConsoleElement case
     if (element instanceof PydevConsoleElement){
       return PydevConsoleElement.generateDoc((PydevConsoleElement)element);
diff --git a/python/src/com/jetbrains/python/documentation/PythonExternalDocumentationProvider.java b/python/src/com/jetbrains/python/documentation/PythonExternalDocumentationProvider.java
index 3a218afd9593..febe61a59cf3 100644
--- a/python/src/com/jetbrains/python/documentation/PythonExternalDocumentationProvider.java
+++ b/python/src/com/jetbrains/python/documentation/PythonExternalDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.jetbrains.python.documentation;
 
 import com.google.common.base.Suppliers;
@@ -22,6 +22,7 @@ import com.jetbrains.python.PyBundle;
 import com.jetbrains.python.psi.PyFile;
 import com.jetbrains.python.psi.resolve.QualifiedNameFinder;
 import com.jetbrains.python.pyi.PyiFile;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jsoup.HttpStatusException;
 import org.jsoup.Jsoup;
@@ -38,7 +39,7 @@ public class PythonExternalDocumentationProvider extends PythonDocumentationProv
   private static final Logger LOG = Logger.getInstance(PythonExternalDocumentationProvider.class);
 
   @Override
-  public String fetchExternalDocumentation(Project project, PsiElement element, List<String> docUrls, boolean onHover) {
+  public @Nls String fetchExternalDocumentation(Project project, PsiElement element, List<String> docUrls, boolean onHover) {
     PsiNamedElement namedElement = ApplicationManager.getApplication().runReadAction((Computable<PsiNamedElement>)() -> {
       PsiElement moduleAnchor = element instanceof PsiDirectory ? element : element.getContainingFile();
       final Module module = ModuleUtilCore.findModuleForPsiElement(moduleAnchor);
diff --git a/xml/dom-impl/src/com/intellij/util/xml/DomDocumentationProvider.java b/xml/dom-impl/src/com/intellij/util/xml/DomDocumentationProvider.java
index 0de7b4e4ced7..6983ce3d7775 100644
--- a/xml/dom-impl/src/com/intellij/util/xml/DomDocumentationProvider.java
+++ b/xml/dom-impl/src/com/intellij/util/xml/DomDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.util.xml;
 
 import com.intellij.lang.documentation.DocumentationProvider;
@@ -6,6 +6,7 @@ import com.intellij.pom.PomTarget;
 import com.intellij.pom.PomTargetPsiElement;
 import com.intellij.psi.DelegatePsiTarget;
 import com.intellij.psi.PsiElement;
+import org.jetbrains.annotations.Nls;
 
 /**
  * @author Dmitry Avdeev
@@ -13,7 +14,7 @@ import com.intellij.psi.PsiElement;
 public class DomDocumentationProvider implements DocumentationProvider {
 
   @Override
-  public String generateDoc(PsiElement element, final PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, final PsiElement originalElement) {
     if (element instanceof PomTargetPsiElement) {
       PomTarget target = ((PomTargetPsiElement)element).getTarget();
       if (target instanceof DelegatePsiTarget) {
diff --git a/xml/impl/src/com/intellij/xml/util/documentation/HtmlDocumentationProvider.java b/xml/impl/src/com/intellij/xml/util/documentation/HtmlDocumentationProvider.java
index 49551a08d8ce..523296bf0fb9 100644
--- a/xml/impl/src/com/intellij/xml/util/documentation/HtmlDocumentationProvider.java
+++ b/xml/impl/src/com/intellij/xml/util/documentation/HtmlDocumentationProvider.java
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.xml.util.documentation;
 
 import com.intellij.documentation.mdn.MdnSymbolDocumentation;
@@ -18,6 +18,7 @@ import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.xml.XmlElementDescriptor;
 import com.intellij.xml.util.XmlUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -51,7 +52,7 @@ public class HtmlDocumentationProvider implements DocumentationProvider {
 
   @Override
   @Nullable
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (element instanceof SchemaPrefix) {
       return ((SchemaPrefix)element).getQuickNavigateInfo();
     }
@@ -70,7 +71,7 @@ public class HtmlDocumentationProvider implements DocumentationProvider {
   }
 
   @Override
-  public String generateDoc(PsiElement element, PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
     String result = generateDocForHtml(element, originalElement);
     if (result != null) return result;
     return generateDocFromStyleOrScript(element, originalElement);
diff --git a/xml/impl/src/com/intellij/xml/util/documentation/XmlDocumentationProvider.java b/xml/impl/src/com/intellij/xml/util/documentation/XmlDocumentationProvider.java
index 0333db48733a..c3ebb7777aa5 100644
--- a/xml/impl/src/com/intellij/xml/util/documentation/XmlDocumentationProvider.java
+++ b/xml/impl/src/com/intellij/xml/util/documentation/XmlDocumentationProvider.java
@@ -1,4 +1,4 @@
-// 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.xml.util.documentation;
 
 import com.intellij.lang.Language;
@@ -22,6 +22,7 @@ import com.intellij.util.Processor;
 import com.intellij.xml.*;
 import com.intellij.xml.impl.schema.*;
 import com.intellij.xml.util.XmlUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -43,7 +44,7 @@ public class XmlDocumentationProvider implements DocumentationProvider {
 
   @Override
   @Nullable
-  public String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
+  public @Nls String getQuickNavigateInfo(PsiElement element, PsiElement originalElement) {
     if (element instanceof SchemaPrefix) {
       return ((SchemaPrefix)element).getQuickNavigateInfo();
     }
@@ -76,7 +77,7 @@ public class XmlDocumentationProvider implements DocumentationProvider {
   }
 
   @Override
-  public String generateDoc(PsiElement element, final PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, final PsiElement originalElement) {
     if (element instanceof XmlElementDecl) {
       PsiElement curElement = XmlUtil.findPreviousComment(element);
 
diff --git a/xml/relaxng/src/org/intellij/plugins/relaxNG/RngDocumentationProvider.java b/xml/relaxng/src/org/intellij/plugins/relaxNG/RngDocumentationProvider.java
index 311493a7d912..d1184ce221ae 100644
--- a/xml/relaxng/src/org/intellij/plugins/relaxNG/RngDocumentationProvider.java
+++ b/xml/relaxng/src/org/intellij/plugins/relaxNG/RngDocumentationProvider.java
@@ -29,6 +29,7 @@ import it.unimi.dsi.fastutil.objects.ReferenceOpenHashSet;
 import org.intellij.plugins.relaxNG.model.descriptors.CompositeDescriptor;
 import org.intellij.plugins.relaxNG.model.descriptors.RngElementDescriptor;
 import org.intellij.plugins.relaxNG.model.descriptors.RngXmlAttributeDescriptor;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.Nullable;
 import org.kohsuke.rngom.digested.DElementPattern;
@@ -44,7 +45,7 @@ final class RngDocumentationProvider implements DocumentationProvider {
 
   @Override
   @Nullable
-  public String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
+  public @Nls String generateDoc(PsiElement element, @Nullable PsiElement originalElement) {
     final XmlElement c = PsiTreeUtil.getParentOfType(originalElement, XmlTag.class, XmlAttribute.class);
     if (c != null && c.getManager() == null) {
       LOG.warn("Invalid context element passed to generateDoc()", new Throwable("<stack trace>"));
diff --git a/xml/relaxng/src/org/intellij/plugins/relaxNG/compact/RngCompactLanguage.java b/xml/relaxng/src/org/intellij/plugins/relaxNG/compact/RngCompactLanguage.java
index e58057b0ac7d..3d0e229a4a6a 100644
--- a/xml/relaxng/src/org/intellij/plugins/relaxNG/compact/RngCompactLanguage.java
+++ b/xml/relaxng/src/org/intellij/plugins/relaxNG/compact/RngCompactLanguage.java
@@ -32,6 +32,7 @@ import org.intellij.plugins.relaxNG.compact.psi.RncDefine;
 import org.intellij.plugins.relaxNG.compact.psi.RncElement;
 import org.intellij.plugins.relaxNG.compact.psi.util.EscapeUtil;
 import org.intellij.plugins.relaxNG.compact.psi.util.RenameUtil;
+import org.jetbrains.annotations.Nls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -117,7 +118,7 @@ public final class RngCompactLanguage extends Language {
 
     @Override
     @Nullable
-    public String generateDoc(PsiElement element, PsiElement originalElement) {
+    public @Nls String generateDoc(PsiElement element, PsiElement originalElement) {
       if (element instanceof RncElement) {
         PsiElement comment = element.getPrevSibling();
         while (comment instanceof PsiWhiteSpace) {
diff --git a/xml/xml-psi-impl/src/com/intellij/documentation/mdn/XmlMdnDocumentationProvider.kt b/xml/xml-psi-impl/src/com/intellij/documentation/mdn/XmlMdnDocumentationProvider.kt
index caaba18f558d..bb0beb940c13 100644
--- a/xml/xml-psi-impl/src/com/intellij/documentation/mdn/XmlMdnDocumentationProvider.kt
+++ b/xml/xml-psi-impl/src/com/intellij/documentation/mdn/XmlMdnDocumentationProvider.kt
@@ -1,4 +1,4 @@
-// Copyright 2000-2021 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.
+// Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.documentation.mdn
 
 import com.intellij.lang.documentation.DocumentationProvider
@@ -11,13 +11,14 @@ import com.intellij.psi.xml.XmlTag
 import com.intellij.psi.xml.XmlToken
 import com.intellij.xml.util.HtmlUtil
 import com.intellij.xml.util.XmlUtil
+import org.jetbrains.annotations.Nls
 
 class XmlMdnDocumentationProvider : DocumentationProvider {
 
   override fun getUrlFor(element: PsiElement, originalElement: PsiElement?): List<String>? =
     getMdnDocumentation(element, originalElement)?.let { listOf(it.url) }
 
-  override fun generateDoc(element: PsiElement, originalElement: PsiElement?): String?  =
+  override fun generateDoc(element: PsiElement, originalElement: PsiElement?): @Nls String?  =
     getMdnDocumentation(element, originalElement)?.getDocumentation(true)
 
   companion object {