Custom filters for log4net (well, one at least so far)
<appender>
....
<filter type="Shorthand.log4net.Filters.ExceptionFilter">
<exceptionTypeName value="Shorthand.log4net.Filters.Tests.UnimportantException, Shorthand.log4net.Filters.Tests, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />
<acceptOnMatch value="false" />
</filter>
</appender>