Node type: Element (may contain text and/or other elements)
Whitespace: Protected
A chapter, lesson, or topic number.
<titleBlock>
<titleNumber paraID="1">Section 1</titleNumber>
<title paraID="2">The Lord’s Preface: “The Voice of Warning”</title>
</titleBlock>
Use paragraph styles like CHAP_titleNumber, COVERFR_titleNumber, and ARTCL_titleNumber.