+Running tests by tags
+---------------------
+
+Tests can also be filtered by Junit tags or tag expressions [1], for example to
+run only the Log4 1.x agent tests:
+
+ mvn clean verify -Dgroups='agent:log4j'
+
+Or to exclude the tests of the Log4j2 domain:
+
+ mvn clean verify -Dgroups='!domain:log4j2'
+
+[1] https://junit.org/junit5/docs/current/user-guide/#running-tests-tags
+