Tax Hiearchy for the Contract Billing Module

Hello,

I am trying to find a Hierarchy on how E1 applies Tax within the Contract Billing Module.

I know that in Service Billing, the system first looks at the F48127, then it will look at the WO master , then it looks at the JOB master and finally looks at the customer master to get tax information.

Is there something  similar in the Contract Billing World.

1) When Vertex "O" is installed

2) When STD E1 Taxation is used.

Any help will be appreciated.

Thanks