2.1.1.1 Main Document
Content Type:
application/vnd.ms-word.document.macroEnabled.main+xml
application/vnd.ms-word.template.macroEnabledTemplate.main+xml
Root Namespace: http://schemas.openxmlformats.org/wordprocessingml/2006/main
Source Relationship:http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument
The part is specified in [ECMA-376] Part 1, Section 11.3.10.