Hi, I want this: logger.debug("Test logging: ", new IllegalStateException("Wibble")); to give me a full stack trace, and this: logger.debug(MarkerFactory.getMarker("MINIMAL_EXCEPTION"), "Test logging: ", new IllegalStateException("Wibble")); to just output the class and message. I don't have Janino, and I'm trying to keep it all as small as possible (also not sure I could pay the price of expression evaluation for each message). The closest I've got is this: <evaluator name="DISPLAY_EX_EVAL" class="ch.qos.logback.classic.boolex.OnMarkerEvaluator"> <marker>MINIMAL_EXCEPTION</marker> </evaluator> <appender name="STDOUTPUT" class="ch.qos.logback.core.ConsoleAppender"> <encoder> <charset>UTF-8</charset> <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} %line - %msg%ex{full, DISPLAY_EX_EVAL}%n</pattern> </encoder> </appender> <contextListener class="ch.qos.logback.classic.jul.LevelChangePropagator" /> But that doesn't output exception at all when the Marker is present. Is there any way to get what I want without a more complex expression? Thanks. Jim