diff --git a/multi/multi__propagation.html b/multi/multi__propagation.html
index 58648a9d5..59db7f498 100644
--- a/multi/multi__propagation.html
+++ b/multi/multi__propagation.html
@@ -56,8 +56,7 @@ With the <code class="literal">spring.sleuth.baggage-keys</code>, you set keys t
 You can also use the <code class="literal">spring.sleuth.propagation-keys</code> property to pass a list of prefixed keys that are whitelisted without any prefix.
 Notice that there&#8217;s no <code class="literal">x-</code> in front of the header keys.</p></td></tr></table></div><p>In order to automatically set the baggage values to Slf4j&#8217;s MDC, you have to set
 the <code class="literal">spring.sleuth.log.slf4j.whitelisted-mdc-keys</code> property with a list of whitelisted
-baggage keys. E.g. <code class="literal">spring.sleuth.log.slf4j.whitelisted-mdc-keys=foo</code> will set the value of the
-<code class="literal">foo</code> baggage into MDC.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_extracting_a_propagated_context" href="#_extracting_a_propagated_context"></a>5.1.2&nbsp;Extracting a Propagated Context</h3></div></div></div><p>The <code class="literal">TraceContext.Extractor&lt;C&gt;</code> reads trace identifiers and sampling status from an incoming request or message.
+baggage and propagation keys. E.g. <code class="literal">spring.sleuth.log.slf4j.whitelisted-mdc-keys=foo</code> will set the value of the <code class="literal">foo</code> baggage into MDC.</p><div class="important" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Important"><tr><td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="images/important.png"></td><th align="left">Important</th></tr><tr><td align="left" valign="top"><p>Remember that adding entries to MDC can drastically decrease the performance of your application!</p></td></tr></table></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_extracting_a_propagated_context" href="#_extracting_a_propagated_context"></a>5.1.2&nbsp;Extracting a Propagated Context</h3></div></div></div><p>The <code class="literal">TraceContext.Extractor&lt;C&gt;</code> reads trace identifiers and sampling status from an incoming request or message.
 The carrier is usually a request object or headers.</p><p>This utility is used in standard instrumentation (such as <code class="literal">HttpServerHandler`</code>) but can also be used for custom RPC or messaging code.</p><p><code class="literal">TraceContextOrSamplingFlags</code> is usually used only with <code class="literal">Tracer.nextSpan(extracted)</code>, unless you are
 sharing span IDs between a client and a server.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_sharing_span_ids_between_client_and_server" href="#_sharing_span_ids_between_client_and_server"></a>5.1.3&nbsp;Sharing span IDs between Client and Server</h3></div></div></div><p>A normal instrumentation pattern is to create a span representing the server side of an RPC.
 <code class="literal">Extractor.extract</code> might return a complete trace context when applied to an incoming client request.
diff --git a/single/spring-cloud-sleuth.html b/single/spring-cloud-sleuth.html
index f2e2cde89..a60840972 100644
--- a/single/spring-cloud-sleuth.html
+++ b/single/spring-cloud-sleuth.html
@@ -485,8 +485,7 @@ With the <code class="literal">spring.sleuth.baggage-keys</code>, you set keys t
 You can also use the <code class="literal">spring.sleuth.propagation-keys</code> property to pass a list of prefixed keys that are whitelisted without any prefix.
 Notice that there&#8217;s no <code class="literal">x-</code> in front of the header keys.</p></td></tr></table></div><p>In order to automatically set the baggage values to Slf4j&#8217;s MDC, you have to set
 the <code class="literal">spring.sleuth.log.slf4j.whitelisted-mdc-keys</code> property with a list of whitelisted
-baggage keys. E.g. <code class="literal">spring.sleuth.log.slf4j.whitelisted-mdc-keys=foo</code> will set the value of the
-<code class="literal">foo</code> baggage into MDC.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_extracting_a_propagated_context" href="#_extracting_a_propagated_context"></a>5.1.2&nbsp;Extracting a Propagated Context</h3></div></div></div><p>The <code class="literal">TraceContext.Extractor&lt;C&gt;</code> reads trace identifiers and sampling status from an incoming request or message.
+baggage and propagation keys. E.g. <code class="literal">spring.sleuth.log.slf4j.whitelisted-mdc-keys=foo</code> will set the value of the <code class="literal">foo</code> baggage into MDC.</p><div class="important" style="margin-left: 0.5in; margin-right: 0.5in;"><table border="0" summary="Important"><tr><td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="images/important.png"></td><th align="left">Important</th></tr><tr><td align="left" valign="top"><p>Remember that adding entries to MDC can drastically decrease the performance of your application!</p></td></tr></table></div></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_extracting_a_propagated_context" href="#_extracting_a_propagated_context"></a>5.1.2&nbsp;Extracting a Propagated Context</h3></div></div></div><p>The <code class="literal">TraceContext.Extractor&lt;C&gt;</code> reads trace identifiers and sampling status from an incoming request or message.
 The carrier is usually a request object or headers.</p><p>This utility is used in standard instrumentation (such as <code class="literal">HttpServerHandler`</code>) but can also be used for custom RPC or messaging code.</p><p><code class="literal">TraceContextOrSamplingFlags</code> is usually used only with <code class="literal">Tracer.nextSpan(extracted)</code>, unless you are
 sharing span IDs between a client and a server.</p></div><div class="section"><div class="titlepage"><div><div><h3 class="title"><a name="_sharing_span_ids_between_client_and_server" href="#_sharing_span_ids_between_client_and_server"></a>5.1.3&nbsp;Sharing span IDs between Client and Server</h3></div></div></div><p>A normal instrumentation pattern is to create a span representing the server side of an RPC.
 <code class="literal">Extractor.extract</code> might return a complete trace context when applied to an incoming client request.
diff --git a/spring-cloud-sleuth.xml b/spring-cloud-sleuth.xml
index 085d6369b..08d568dec 100644
--- a/spring-cloud-sleuth.xml
+++ b/spring-cloud-sleuth.xml
@@ -1060,8 +1060,10 @@ Notice that there&#8217;s no <literal>x-</literal> in front of the header keys.<
 </important>
 <simpara>In order to automatically set the baggage values to Slf4j&#8217;s MDC, you have to set
 the <literal>spring.sleuth.log.slf4j.whitelisted-mdc-keys</literal> property with a list of whitelisted
-baggage keys. E.g. <literal>spring.sleuth.log.slf4j.whitelisted-mdc-keys=foo</literal> will set the value of the
-<literal>foo</literal> baggage into MDC.</simpara>
+baggage and propagation keys. E.g. <literal>spring.sleuth.log.slf4j.whitelisted-mdc-keys=foo</literal> will set the value of the <literal>foo</literal> baggage into MDC.</simpara>
+<important>
+<simpara>Remember that adding entries to MDC can drastically decrease the performance of your application!</simpara>
+</important>
 </section>
 <section xml:id="_extracting_a_propagated_context">
 <title>Extracting a Propagated Context</title>