Hi all, Just an update on the statistics regarding the generation of logging event with localized level names. I forgot to mention that the statistics I reported in my previous mail were related to the generation of logging event in which also the string "Caller+" (generated by the conversion word caller) and messages were localized, not only the level names. To localize the string "Caller+" I tried both an approach based on Ceki idea (i.e., I implemented a customized CallerDataConverter), and an approach based on the modification of the class CallerDataConverter. To localize log messages I followed the instructions reported at http://www.slf4j.org/localization.html. Today I made a little modification to my version of CallerDataConverter. Now my application on an input that leads to the generation of about 63000 logging events runs in about 28 seconds (instead of 46) using my modified version of logback-classic. The number of invocations of MakePropertyResourceBoundle is 14 (instead of 266). Hence, the internationalization of level names and the string "Caller+" obtained modifying logbcak-classic classes seems to be more efficient than the internationalization based on custom converters for new conversion words. This due to the reduced number of invocations of the method MakePropertyResourceBoundle of CAL10N. Dario