diff --git a/spring-web/src/main/java/org/springframework/http/HttpHeaders.java b/spring-web/src/main/java/org/springframework/http/HttpHeaders.java
index 7ac9a382ca..5d895e4a36 100644
--- a/spring-web/src/main/java/org/springframework/http/HttpHeaders.java
+++ b/spring-web/src/main/java/org/springframework/http/HttpHeaders.java
@@ -83,6 +83,10 @@ import org.springframework.util.StringUtils;
  * over the old instance's {@code entrySet()} and using
  * {@link #addAll(String, List)} rather than {@link #put(String, List)}.
  *
+ * <p>This class is meant to reference "well-known" headers supported by Spring
+ * Framework. If your application or library relies on other headers defined in RFCs,
+ * please use methods that accept the header name as a parameter.
+ *
  * @author Arjen Poutsma
  * @author Sebastien Deleuze
  * @author Brian Clozel
diff --git a/spring-web/src/main/java/org/springframework/http/MediaType.java b/spring-web/src/main/java/org/springframework/http/MediaType.java
index f2fa5b61ed..ff27cb0ea3 100644
--- a/spring-web/src/main/java/org/springframework/http/MediaType.java
+++ b/spring-web/src/main/java/org/springframework/http/MediaType.java
@@ -39,6 +39,10 @@ import org.springframework.util.StringUtils;
  * A subclass of {@link MimeType} that adds support for quality parameters
  * as defined in the HTTP specification.
  *
+ * <p>This class is meant to reference media types supported by Spring Framework.
+ * If your application or library relies on other media types defined in RFCs,
+ * please use {@link #parseMediaType(String)} or a custom utility class.
+ *
  * @author Arjen Poutsma
  * @author Juergen Hoeller
  * @author Rossen Stoyanchev
diff --git a/spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientIntegrationTests.java b/spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientIntegrationTests.java
index 69f656c82f..35abb5e76a 100644
--- a/spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientIntegrationTests.java
+++ b/spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientIntegrationTests.java
@@ -83,6 +83,7 @@ import org.springframework.web.reactive.function.client.WebClient.ResponseSpec;
 import org.springframework.web.testfixture.xml.Pojo;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assumptions.assumeFalse;
 import static org.junit.jupiter.params.provider.Arguments.argumentSet;
 
 /**
@@ -192,6 +193,8 @@ class WebClientIntegrationTests {
 
 	@ParameterizedWebClientTest
 	void applyAttributesToNativeRequest(ClientHttpConnector connector) {
+		assumeFalse(connector instanceof ReactorClientHttpConnector,
+				"Temporarily disabling flaky test for Reactor Netty");
 		startServer(connector);
 		prepareResponse(response -> {});