How to use Create VM Template Advanced Options in Opennebula 5.2.1?

I want to know what is advanced options for VM Template and Service Template Create. Provide me some sample template scripts. What is the script format and syntax?

VM Template Reference: http://docs.opennebula.org/5.2/operation/references/template.html

Service Template Reference: http://docs.opennebula.org/5.2/integration/system_interfaces/appflow_api.html#appflow-api