diff --git a/topics/preface.adoc b/topics/preface.adoc
index 3a0cd073cb..485aff32dc 100755
--- a/topics/preface.adoc
+++ b/topics/preface.adoc
@@ -18,3 +18,21 @@ Let's pretend to have an extremely long line that does not fit
 This one is short
 ----      
 
+{% if community %}
+  community set
+{% else %}
+  community VARIABLE NOT SET
+{% endif %}
+
+{% if book.community %}
+  book.community set
+{% else %}
+  book.community VARIABLE NOT SET
+{% endif %}
+
+{% if product %}
+  PRODUCT!
+{% else %}
+  product VARIABLE NOT SET
+{% endif %}
+