http://docs.jboss.org/mod_cluster/1.1.0/html/UsingSSL.html

Section: 11.1.4.3. Create the client certificate

Step 2
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mkdir -p CERTS/Client
cd CERTS/Client
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This is incorrect, it is the copy of step 1 instead of how to actually "Create a new request and sign it for the client certificate and key of the JBossWEB part."