Purpose of nutrient_incoming_name table

I wonder what the nutrient_incoming_name table is used for. In particular, it is unclear to me what ‘incoming nutrient data’ are. Are these synonyms for the nutrients used by USDA? Is the file meant to make connections of nutrients from other databases to USDA nutrients?
For example, there are these 15 entries for protein (nutrient_id=1003):

Protein
Proteins
PROTEIN (N X 5.70) D
PROTEIN (N X 6.38) D
PROTEIN(N X 6.25)DUM
Protein - Kjeldahl
PROTEIN avg
PROTEIN(N X 6.25)DUMAS
PROTEIN (N X 5.70) DUMAS
PROTEIN (N X 6.38) DUMAS
Protein - Combustion (N X 6.25)
PROTEIN (N X 5.46) DUMAS
Protein (N x 6.25) Dumas Method
Protein (N x 6.38) Dumas Method
Protein (N x 5.30) Dumas Method

So, will both ‘PROTEIN(N X 6.25)DUMAS’ and ‘Protein (N x 5.30) Dumas Method’ be assigned the same nutrient_id even though they were multiplied by different factors? So if a nutrient in another database has one of these 15 names for protein, does it get converted to the nutrient_id=1003 in the USDA database?

Answer from USDA:

The nutrient id is linked to a naming convention for a specific analytical method by laboratory. For example, one lab may identify protein as Protein (N x 6.25) Dumas Method and another lab may call protein as PROTEIN(N X 6.25)DUMAS. It is all the same protein, however laboratories component names are not consistent across labs.
Protein is a bit complex because the values for protein are calculated from the amount of total nitrogen (N) in the food, using the specific conversion factors recommended by Jones (1941) for most food items. The analytical methods used to determine the nitrogen content of foods are AOAC 968.06 (4.2.04), 992.15 (39.1.16) and 990.03 (combustion) and 991.20 (Kjeldahl) (AOAC, 2012). The general factor of 6.25 is used to calculate protein in items that do not have a specific factor.
Protein values for chocolate, cocoa, coffee, mushrooms, and yeast are adjusted for non-protein nitrogenous material (Merrill and Watt, 1973). The adjusted protein
conversion factors used to calculate protein for these items are as follows:

chocolate and cocoa 4.74
coffee 5.3
mushrooms 4.38
yeast 5.7