Thanks for your great reply.
I have further some doubts on ACBR. Some people(in general) refer "list of billable items" which needs to be included in bill/invoice, is each Applied Customer Billing Rate (ACBR) or charge is equivalent or same as billing item?. or both are used as interchangeably names.
Dear if possible just have a look on below link and pls also clarify my doubts.
Kindly clarify my doubts