Column Subpart Name in Material Content report

The column Subpart Name in the material content report , pulls the data from page 3 of IPC file and is usually  filled inconsistently by suppliers since there is no standard defined. As this doesn’t carry any impact on the material content or calculations, this has been ignored. Data from homogenous material in IPC declaration is captured in material in the report. Is there any defined standard/guideline from IPC on what data needs to be filled by component manaufcaturers