diff --git a/config/configuration.sample.yml b/config/configuration.sample.yml
index 050b6562c1..982e4aef28 100644
--- a/config/configuration.sample.yml
+++ b/config/configuration.sample.yml
@@ -90,7 +90,9 @@ main:
             client_secret: null
 border-manager:
     enabled: true
-    extension-mapping: { }
+    extension-mapping:
+        otc: application/vnd.oasis.opendocument.chart-template
+        ttc: application/x-font-ttf
     checkers:
         -
             type: Checker\Sha256
diff --git a/resources/www/common/images/icons/substitution/application_vnd.oasis.opendocument.chart-template.png b/resources/www/common/images/icons/substitution/application_vnd.oasis.opendocument.chart-template.png
new file mode 100644
index 0000000000..005ad6fe8b
Binary files /dev/null and b/resources/www/common/images/icons/substitution/application_vnd.oasis.opendocument.chart-template.png differ