This section describes the sectioning commands for tt(article)s, tt(report)s, 
tt(book)s and for tt(plainhtml). The document type tt(manpage) defines its own 
sectioning commands which are described in section ref(manpage).


itemize(

    it() tt(part(title)): Starts a new part. Only available in tt(book) 
    documents. 
    
    it() tt(chapter(title)): Starts a new chapter. Only available in tt(book) 
    or tt(report) documents.
    
    it() tt(sect(title)): Starts a section. 
    
    it() tt(subsect(title)): A subsection.
    
    it() tt(subsubsect(title)): A sub-subsection.
    
    it() tt(subsubsubsect(title)): An even smaller sectioning command.
    
)

The macros generate entries in the table of contents and use numbering, which
means that each section is prefixed with a number (1, 1.1, 1.2, and so on). 
The macros are also available with an tt(n) prefix (tt(npart), tt(nchapter), 
tt(nsect) etc.) which generate neither entries in the table of contents nor 
numbers. The tt(n)-versions can be used in, e.g., an article where you only 
want to use the sectioning commands to set captions, but aren't interested in 
numbering. 

The sectioning should start at the top level sections of the available
document: tt(chapter) for reports, tt(sect) for articles, etc.. If you start a
document with a lower sectioning command (e.g., when you start an article with
a tt(subsect)), the numbering of sections may go haywire. The only exception
to this rule is the tt(part) of a tt(book) document: parts are optional, in
books, tt(chapter)s may be the top sectioning commands.
Summarized, in a tt(book) or tt(report) you should start at least with a
tt(chapter). In an tt(article) you should start with a tt(section).

The sectioning commands have a further function: when tt(label) statements 
appear after the sectioning command, then a label name is used as a 
placeholder for the last generated number. This is further described in 
section ref(labels).
