diff --git a/book/chapter-05-gbdialog-reference.md b/book/chapter-05-gbdialog-reference.md
index 49ac9ed9..24bacc32 100644
--- a/book/chapter-05-gbdialog-reference.md
+++ b/book/chapter-05-gbdialog-reference.md
@@ -64,6 +64,7 @@ The following file types are loaded from a .gbdialog package: `.vbs`, `.vb`, `.b
 | field AS dataType| Defines a field in TABLE. Eg.: name string(50). | 
 | FILL| Fills a data into a Word document to be exported as images | 
 | INCLUDE file | Includes a file into .gbdialog | 
+| FORMAT value, format | Formats a value according to format specified. Eg. d = FORMAT today, "YYYY-MM-dd" | 
 
 ### Internal Variables and Functions.