The BtModuleTextModel represents the text of a sword module. It uses an integer index to address each entry (verse, paragraph, etc). The html text is obtained using backend rendering functions. It is then post processed to fix a few things so that the QML ListView works correctly. The ListView supports a "rich text" that is a subset of html. The post processing is done in the class BtTextFilter which is installed into BtModuleTextModel by the frontend.