diff --git a/mailer.rst b/mailer.rst
index 68939c4c3ca..8b4f6d6678b 100644
--- a/mailer.rst
+++ b/mailer.rst
@@ -467,10 +467,18 @@ images inside the HTML contents::
// ...
->embed(fopen('/path/to/images/logo.png', 'r'), 'logo')
->embedFromPath('/path/to/images/signature.gif', 'footer-signature')
+
// reference images using the syntax 'cid:' + "image embed name"
->html(' ...
...')
+
+ // use the same syntax for images included as CSS background images
+ ->html('...