diff --git a/Automatic-output-splitting.md b/Automatic-output-splitting.md
index 6f3300b..98a1185 100644
--- a/Automatic-output-splitting.md
+++ b/Automatic-output-splitting.md
@@ -3,6 +3,7 @@ Input will be automatically split into multiple _MOBI_ files **if correct file s
 
 For now KCC support three directory structures. If none of these structures will be used KCC will try to create a single MOBI file. If input batch is very big conversion might fail due to **KindleGen** or memory  limitations.
 
+Additionally directory structure is used to generate TOC used by all Kindle models.
 
 ![FS](http://kcc.vulturis.eu/img/FS.png)