WARNING: if you use this setting, and then upgrade to a newer release of Lucene, sizable changes may happen. If precise back compatibility is important then you should instead explicitly specify an actual version. If you use this constant then you may need to re-index all of your documents when upgrading Lucene, as the way text is indexed may have changed. Additionally, you may need to re-test your entire application to ensure it behaves as expected, as some defaults may have changed and may break functionality in your application.