Using custom variables.                     
                        
                           
                           
                        
                     
                  
                  
                  One can create custom variables and these can be used within the service definition for defining a service. 
There are 2 main standards for defining custom variables. 
- Custom variables need to be started with an underscore i.e. (_), to avoid name collision with already present standard variables. 
 
- These variables will be converted to uppercase before execution. 
 

 
 
