diff --git a/src/bcf/README.md b/src/bcf/README.md
index aa1e4951e3..71a503f500 100644
--- a/src/bcf/README.md
+++ b/src/bcf/README.md
@@ -3,3 +3,7 @@
 A simple Python implementation of the BCF standard. Manipulation of BCF-XML is
 available via `bcfxml.py` and manipulation of BCF-API is available via
 `bcfapi.py`.
+
+Python files in 'model' folder are automatically generated from .xsd files (located in 'xsd' folder).
+To regenerate them you can use `make models`.
+The only exception is 'v2/model/extensions.py', see it's note for the details.