When using the tomcat7:run-war goal, the context is created based on the path configuration parameter.
To use parallel deployment (http://jagadesh4java.blogspot.be/2013/08/tomcat-7-parallel-deployment.html) I usually append the timestamp to the path as shown below:
This works perfectly when deploying (tomcat7:deploy-only) the war since Tomcat detect the ## and separate the context from the version.
However there the same process is not applied when running the war (tomocat7:run-war) the ## characters are URL encoded as %13%13 and the version (=timestamp) is in the resulting context.
Usually all character should be URL encoded as it is done as the moment, but this case of parallel deployement might be an exception. (feature was introducted in tomcat7).