Hi all, I am experimenting with using multiple channels with Boost.Log. I am using the boost::trivial severity levels, the common attributes, and logging using BOOST_LOG_SEV() using a mix of global and class specific loggers. I am also using boost::log::init_from_stream(std::istream&) to configure sinks from a settings file. I would like to be able to define a sink filter that allows increasing the logging verbosity on just one channel but I am struggling to write succinct filer expressions. E.g given three channels A, B, and C I would like to write: Filter="(%Channel% = \"B\" and %Severity% >= trace) or %Severity% >= warning" to increase the verbosity to trace only on channel B, but this doesn't work. I am finding I have to write: Filter="(%Channel% = \"B\" and %Severity% >= trace) or (%Channel% != \"B\" and %Severity% >= warning)" Is this expected behaviour? If so then declaring more complex filtering will become burdensome. Regards Bill Somerville.