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Section Numbering
§4.3.1 Numbering scheme
The numbering scheme derives from the filesystem structure:
| Level | Source | Format |
|---|---|---|
| Chapter | Directory numeric prefix | N |
| Section | File numeric prefix within chapter | N.M |
| Subsection | ## heading order within file |
N.M.K |
| Sub-subsection | ### heading order within parent ## |
N.M.K.L |
| (deeper) | Each heading level adds a dot-separated component | unlimited depth |
Chapter directories MUST use the format N-name/ where N is a positive integer. Files within chapters MUST use the format N-name.md where N is a positive integer.
Chapter and section numbering MUST start at 1 within their parent. Numbers MUST be sequential -- gaps SHOULD NOT exist in finalized versions but MAY exist in drafts.
§4.3.2 Subsection numbering
Subsections are numbered by the sequential order of headings within a file, not by explicit numeric prefixes. The first ## heading in a file is subsection 1, the second is subsection 2, and so on. Nested headings (###, ####) restart numbering within their parent heading.
3-security-descriptors/2-acls.md:
## Overview ← §3.2.1
## ACE Ordering ← §3.2.2
### By Type ← §3.2.2.1
### By Position ← §3.2.2.2
## Inheritance ← §3.2.3
The chapter number (3) comes from the directory prefix. The section number (2) comes from the file prefix. Subsection numbers come from heading order.
§4.3.3 Files without subsection headings
A section file with no ## headings has no subsections. Content is addressed at the section level: §3.2, §3.2(1).
§4.3.4 Stability
Section numbers are positional. Inserting a chapter shifts all subsequent chapter numbers. Inserting a file shifts subsequent section numbers within that chapter. Inserting a ## heading shifts subsequent subsection numbers within that file.
Within a final version, the structure MUST NOT change. Section numbers are frozen on finalisation.
When a new version restructures content, the changelog (see §7.1) MUST document structural changes that affect numbering.