$string['numbering_help']='* None - chapter and subchapter titles are not formatted at all, use if you want to define special numbering styles. For example letters: in chapter title type "A First Chapter", "A.1 Some Subchapter",...
* Numbers - chapters and subchapters are numbered (1, 1.1, 1.2, 2, ...)
* Bullets - subchapters are indented and displayed with bullets