diff --git a/Documentation/README.md b/Documentation/README.md
index 03e1bed4..291a700a 100644
--- a/Documentation/README.md
+++ b/Documentation/README.md
@@ -29,7 +29,8 @@ Globally Unique ID in the IFC format. This format is used only when referring to
 * This document describes the BCF format that is used to exchange topics, such as, issues, scenes, etc. between different BIM software.
 
 ### BCF file structure
-A BCF file is a zip containing one folder for each topic. The root of the BCF zip contains the following files.
+A BCF file is a zip containing one folder for each topic with its file extension "bcfzip" for BCFv1.0 and BCFv2.0. The file extension as the version number "bcfv2.1" is introduced since BCFv2.1.
+The root of the BCF zip contains the following files.
 
 * project.bcfp (optional)
     - An XML file referencing the extension.xsd to a project. The schema for this file is project.xsd.
diff --git a/Extension Schemas/extensions.xsd b/Extension Schemas/extensions.xsd
index e2aeaebd..51304a8c 100644
--- a/Extension Schemas/extensions.xsd	
+++ b/Extension Schemas/extensions.xsd	
@@ -28,7 +28,7 @@
 				<xs:enumeration value="Structure"/>
 				<xs:enumeration value="Mechanical"/>
 				<xs:enumeration value="Electrical"/>
-				<xs:enumeration value="Specifications"/>
+				<xs:enumeration value="Spesifications"/>
 				<xs:enumeration value="Technology"/>
 			</xs:restriction>
 		</xs:simpleType>