diff --git a/app/templates/partials/templates/guidance-optional-content.html b/app/templates/partials/templates/guidance-optional-content.html
new file mode 100644
index 000000000..0d8b19ca6
--- /dev/null
+++ b/app/templates/partials/templates/guidance-optional-content.html
@@ -0,0 +1,20 @@
+<h2 class="heading-medium">
+  Optional content
+</h2>
+<p>
+  Use double brackets and ‘??’ to define optional content.
+</p>
+<p>
+  For example if you only want to show something to people who are under
+  18:
+</p>
+<div class="panel panel-border-wide">
+  <p>
+    ((under18??Please get your application signed by a parent or
+    guardian.))
+  </p>
+</div>
+<p>
+  For each person you send this message to, specify ‘yes’ or ‘no’ to
+  show or hide this content.
+</p>
diff --git a/app/templates/views/edit-email-template.html b/app/templates/views/edit-email-template.html
index 669b0e278..5e90f48b1 100644
--- a/app/templates/views/edit-email-template.html
+++ b/app/templates/views/edit-email-template.html
@@ -29,6 +29,7 @@
         <aside class="column-whole">
           {% include "partials/templates/guidance-formatting.html" %}
           {% include "partials/templates/guidance-personalisation.html" %}
+          {% include "partials/templates/guidance-optional-content.html" %}         
           {% include "partials/templates/guidance-links.html" %}
         </aside>
       </div>
diff --git a/app/templates/views/edit-sms-template.html b/app/templates/views/edit-sms-template.html
index 4c302d507..6f8ab64f8 100644
--- a/app/templates/views/edit-sms-template.html
+++ b/app/templates/views/edit-sms-template.html
@@ -27,6 +27,7 @@
         </div>
         <aside class="column-whole">
           {% include "partials/templates/guidance-personalisation.html" %}
+          {% include "partials/templates/guidance-optional-content.html" %}
           {% include "partials/templates/guidance-links.html" %}
           {% include "partials/templates/guidance-character-count.html" %}
         </aside>