diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php
index 3cbe534fb9..f49f6a18c0 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php
@@ -21,7 +21,7 @@ use Symfony\Component\DependencyInjection\ContainerBuilder;
  */
 class UnusedTagsPass implements CompilerPassInterface
 {
-    private $whitelist = [
+    private $knownTags = [
         'annotations.cached_reader',
         'auto_alias',
         'cache.pool',
@@ -70,11 +70,11 @@ class UnusedTagsPass implements CompilerPassInterface
 
     public function process(ContainerBuilder $container)
     {
-        $tags = array_unique(array_merge($container->findTags(), $this->whitelist));
+        $tags = array_unique(array_merge($container->findTags(), $this->knownTags));
 
         foreach ($container->findUnusedTags() as $tag) {
-            // skip whitelisted tags
-            if (\in_array($tag, $this->whitelist)) {
+            // skip known tags
+            if (\in_array($tag, $this->knownTags)) {
                 continue;
             }
 
diff --git a/src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-tags-whitelist.php b/src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-known-tags.php
similarity index 82%
rename from src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-tags-whitelist.php
rename to src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-known-tags.php
index 7f24973cd8..ec9ae1f97c 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-tags-whitelist.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-known-tags.php
@@ -15,5 +15,5 @@ use Symfony\Bundle\FrameworkBundle\Tests\DependencyInjection\Compiler\UnusedTags
 
 $target = dirname(__DIR__, 2).'/DependencyInjection/Compiler/UnusedTagsPass.php';
 $contents = file_get_contents($target);
-$contents = preg_replace('{private \$whitelist = \[(.+?)\];}sm', "private \$whitelist = [\n        '".implode("',\n        '", UnusedTagsPassUtils::getDefinedTags())."',\n    ];", $contents);
+$contents = preg_replace('{private \$knownTags = \[(.+?)\];}sm', "private \$knownTags = [\n        '".implode("',\n        '", UnusedTagsPassUtils::getDefinedTags())."',\n    ];", $contents);
 file_put_contents($target, $contents);
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/UnusedTagsPassTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/UnusedTagsPassTest.php
index a73cdd1671..8343d0d997 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/UnusedTagsPassTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Compiler/UnusedTagsPassTest.php
@@ -35,21 +35,21 @@ class UnusedTagsPassTest extends TestCase
         $this->assertSame([sprintf('%s: Tag "kenrel.event_subscriber" was defined on service(s) "foo", "bar", but was never used. Did you mean "kernel.event_subscriber"?', UnusedTagsPass::class)], $container->getCompiler()->getLog());
     }
 
-    public function testMissingWhitelistTags()
+    public function testMissingKnownTags()
     {
         if (\dirname((new \ReflectionClass(ContainerBuilder::class))->getFileName(), 3) !== \dirname(__DIR__, 5)) {
             $this->markTestSkipped('Tests are not run from the root symfony/symfony metapackage.');
         }
 
-        $this->assertSame(UnusedTagsPassUtils::getDefinedTags(), $this->getWhitelistTags(), 'The src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php file must be updated; run src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-tags-whitelist.php.');
+        $this->assertSame(UnusedTagsPassUtils::getDefinedTags(), $this->getKnownTags(), 'The src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/UnusedTagsPass.php file must be updated; run src/Symfony/Bundle/FrameworkBundle/Resources/bin/check-unused-known-tags.php.');
     }
 
-    private function getWhitelistTags()
+    private function getKnownTags()
     {
         // get tags in UnusedTagsPass
         $target = \dirname(__DIR__, 3).'/DependencyInjection/Compiler/UnusedTagsPass.php';
         $contents = file_get_contents($target);
-        preg_match('{private \$whitelist = \[(.+?)\];}sm', $contents, $matches);
+        preg_match('{private \$knownTags = \[(.+?)\];}sm', $contents, $matches);
         $tags = array_values(array_filter(array_map(function ($str) {
             return trim(preg_replace('{^ +\'(.+)\',}', '$1', $str));
         }, explode("\n", $matches[1]))));
diff --git a/src/Symfony/Component/DependencyInjection/ContainerBuilder.php b/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
index 7c9860b4dc..f6568b3ea3 100644
--- a/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
+++ b/src/Symfony/Component/DependencyInjection/ContainerBuilder.php
@@ -1176,9 +1176,9 @@ class ContainerBuilder extends Container implements TaggedContainerInterface
             $service = null === $r->getConstructor() ? $r->newInstance() : $r->newInstanceArgs($arguments);
             // don't trigger deprecations for internal uses
             // @deprecated since version 3.3, to be removed in 4.0 along with the deprecated class
-            $deprecationWhitelist = ['event_dispatcher' => ContainerAwareEventDispatcher::class];
+            $deprecationAllowlist = ['event_dispatcher' => ContainerAwareEventDispatcher::class];
 
-            if (!$definition->isDeprecated() && 0 < strpos($r->getDocComment(), "\n * @deprecated ") && (!isset($deprecationWhitelist[$id]) || $deprecationWhitelist[$id] !== $class)) {
+            if (!$definition->isDeprecated() && 0 < strpos($r->getDocComment(), "\n * @deprecated ") && (!isset($deprecationAllowlist[$id]) || $deprecationAllowlist[$id] !== $class)) {
                 @trigger_error(sprintf('The "%s" service relies on the deprecated "%s" class. It should either be deprecated or its implementation upgraded.', $id, $r->name), E_USER_DEPRECATED);
             }
         }