Quickbook documents are structured using 'sections'. These are used to generate the table of contents, and, when generating html, to split the document into pages. This is optional but a good idea for all but the simplest of documents.

A sectioned document might look like:

[book Title
    [quickbook 1.5]
]

[section First Section]

[/...]

[endsect]

[section Second Section]

[/...]

[endsect]

Sections start with the section tag, and end with the [endsect] tag. ([/...] is a comment, described later).

Sections can be given an optional id:

[#quickbook.ref.id]
[section:id The Section Title]

id will be the filename of the generated section. If it is not present, "The Section Title" will be normalized and become the id. Valid characters are a-Z, A-Z, 0-9 and _. All non-valid characters are converted to underscore and all upper-case are converted to lower case. Thus: "The Section Title" will be normalized to "the_section_title".

The end of the section can also have an optional id, this is just used to check that it matches the opening of the section.

[section:matching Section with an id]

[/...]

[endsect:matching]

It won't match a generated id, only one that's explicitly specified, so this will be an error, even if quickbook generates the id generated for the section:

[section Generated]

[/...]

[endsect:generated]

Sections can nest, and that results in a hierarchy in the table of contents.