JIRA Client command line options are passed as java properties. For example, to set no.splash property to true, you need to pass -Dno.splash=true option to Java.
Option 1 [Windows]:
jiraclient.exe -J-Dno.splash=true
CODE
Option 2 [All OS]:
java -Xmx256m -Dno.splash=true -jar jiraclient.jar
CODE
Option 3 [All OS]:
Create a file named "jiraclient.properties" and put there the following line: