So as I am winding through the BtS SDK code and the Tech Tree editor code I have found that the bUseLSystem tag is never read by the SDK but it is still defined in several schemas and set in several XML files such as Civ4ImprovementInfos.xml where it is sometimes set and sometimes it isn't. So the question is: Is it safe to not handle this flag at all anymore in the Tech Tree editor or should I add the ability to read in this flag in the tech tree editor just in case it is still being used just not in the SDK?