The header at the top must say "Section 0 Sub-section 0".
1.2 content.
1.3 content.
More 1.3 content, after a page break.
The header at the top must say "Section 1 Sub-section 3".
1.4 content.
2.1 content.
The header at the top should say "Section 2 Sub-section 0" but may be "Section 1 Sub-section 4".
2.2 content.
2.3 content.
2.4 content.