IWORKXMLReader was an (over-engineered) attempt to make use of libxml2's Reader API a bit easier. With the current rewrite of the parser, XML reading is isolated to a few places, so this extra layer is not necessary anymore. It should be replaced by direct use of xmlTextReader* functions. Similar code for the XML parsing loop can be found in src/lib/FB2Parser.cpp in libe-book.
Migrating Whiteboard tags to Keywords: (EasyHack DifficultyBeginner SkillScript TopicCleanup) [NinjaEdit]