[logback-user] Enabling debug for one Marker only ?

Hi, I have seen there is a logger.isDebugEnabled(Marker marker) method. How would I configure I want debug enbled for one Marker only ? Something like : <logger name="mylogger" marker="mymarker"> <level value="DEBUG" /> </logger> I could find the releant documentation. Or should I play with filters ? (but as I understood it, filters happen after the log statement has been issued). Franck