For a line item: freight or special charge; for the total invoice: the total charges -- expressed in the standard monetary denomination for the currency specified

AT301 is the charge per Bill of Lading line item.

Code qualifying the Bill of Lading freight rate

Rate that applies to the specific commodity

Code identifying the type of quantity on which the rate is based

Numeric value of quantity

AT305 is the quantity of units (miles, gallons, deficit weight, etc.) as defined by the qualifier in AT304.

Code identifying the type of Bill of Lading charge

Percentage expressed as a decimal (e.g., 0.0 through 1.0 represents 0% through 100%)

AT307 is the percent discount that was used to determine the charge in AT301.