Most significant abend code
If the analysis of a fault results in more than one abend code being presented, then Fault Analyzer always considers the first abend code (chronologically) the most significant. However, if the Language Environment® CEEWUCHA user condition handler is used (registered via the LE runtime option USRHDLR(CEEWUCHA)), then the final or last abend code is usually the one that provides the most detailed information about the error.