DefaultDimension and AIF web service

Hello,

Does anyone have a sample XML message, showing how to send a DefaultDimension value when calling an AX AIF web service in AX 2012?

The assumption is that the caller does not know anything other than the individual values that should populate in each dimension.
eg. CostCenter = A, Department = B

Let's say we want to send these values with a salesLine that we are creating on a new Sales order via the SalesOrderService.
I'm at a loss as to how the caller would do this.

Thanks,

David