Hello, When I use Log4j, I can add MDC properties to LogginEvent<http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/spi/LoggingEvent.html>by using RewriteAppender<http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/rewrite/RewriteAppender.html>. It's possible because log4j's LoggingEvent is not an interface and it has setProperty()<http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/spi/LoggingEvent.html#setProperty%28java.lang.String,%20java.lang.String%29>method. Is it possible to add or modify MDC properties dynamically in Logback? The reason I need to change MDC properties using appenders is because of some logs from unaccessible threads. I want to add hostname, application name and some of server's infomation to the logs then transfer the logs event to the central log receiver. Thanks.