Using the following command lists all the optional parameters java
"-XX: + UnlockExperimentalVMOptions" can, and -XX:. + UnlockDiagnosticVMOptions lists several different parameters
java -XX:+UnlockDiagnosticVMOptions -XX:+PrintFlagsFinal -version
"-XX: + UnlockExperimentalVMOptions" can, and -XX:. + UnlockDiagnosticVMOptions lists several different parameters