Which Segments require one row to map per part number?

The segments (i.e. tabs) that expect a single row per part are:

Item
Description

The segments that expect multiple (one or more) rows per part are:

Description (by Code)
Price
Multi-Value EXPI Package
Hazardous Material
Attribute
Interchange
Kit
Digital Assets

Notes

Multiple rows are necessary for EXPI codes that can have more than one value for a part such as “Regulating State”, etc.

If the same code is mapped on both the EXPI tab and on the Multi-Value EXPI tab and the EXPI code doesn’t allow multiple values, the value on the Multi-Value tab will overwrite the value on the EXPI tab.

If the code allows multiple values and the value on the EXPI tab is different from those on the Multi-Value tab the value on the EXPI tab will be included.

For Descriptions, if you require a sequence (because it is a repeating group), you must use the Description (by Code) tab. If the same description code is used on the both the Description and Description (by Code) tabs, the Description (by Code) tab will be used.

See this article if you need to add a sequence number to your source data using a query.