## Section43.2Numbering Options

How various items get numbered can be controlled by specifying levels. For pieces of content (e.g. <example>, <fn>, …) the level will be the number of separators in the number, usually periods. To fully understand these options, carefully read Section 26.2 and Section 26.3.

You can stop numbering divisions at some depth. For example, you may want your <book> (without parts) to have numbered <subsection>, but numbers on the few <subsubsection> is just too messy and not necessary. Then you would set the publication file entry

/publication/numbering/divisions/@level


to the value 3 to number <chapter>, <section>, and <subsection>, only. (Note this is the exception, you will get at most two separators in a division number in this case.) So you can think of this as the maximum level for numbers on divisions. Just be careful not to try to number other objects (described next) to a greater level, as that is impossible, and so will generate a warning and the default will be substituted.

For items within a division, various groups of objects are numbered consecutively, with a hierarchy given by a level. These numbers are controlled by

/publication/numbering/blocks/@level
/publication/numbering/projects/@level
/publication/numbering/equations/@level
/publication/numbering/footnotes/@level


whose values should be integers (zero is a possibility) that do not exceed the maximum level specified for divisions.

Chapters of a <book> may start numbering from something other than one. This feature is not available in a book with structural parts (rather than decorative parts). Read about this at the end of Section 26.3 and Best Practice 26.3.1. If you still want to proceed, then set the publication file entry

/publication/numbering/divisions/@chapter-start


to the desired value of the first chapter.

A <book> with <part> may have the parts numbered to reflect two different structures, decorative or structural. Set the publication file entry

/publication/numbering/divisions/@part-structure


to decorative (the default) or structural.

When a <book> is designed to have structural parts, then there is an expectation that the part divisions are important or relevant (at least moreso than in the case of decorative parts). Then, to choose to number objects (blocks, equations, etc.) at level 0, crossing part boundaries, strikes us as an odd choice. So odd that there is a small bug at issue #1650 1 , which might be solved by simply banning this combination.

For more on divisions, and their numbering see Section 4.6.

github.com/PreTeXtBook/pretext/issues/1650