Based on the 6.1 PRD: https://issues.jboss.org/browse/BPMSPL-35. Probably in the Development Guide.
This has now been documented and can be verified here [1]. Moving this to ON_QA. [1] https://documentation-devel.engineering.redhat.com/site/documentation/en-US/Red_Hat_JBoss_BRMS/6.1/html-single/User_Guide/index.html#chap-BRMS_Execution_Server
Verified.