Manufacturer model number
The model identifies a configuration defined by the manufacturer and is often the strongest bridge between retailers. Even so, retailer-exclusive bundles may append or alter model information.
UPC
A Universal Product Code identifies a particular packaged retail item. Different pack sizes or bundles should carry different UPCs, making it useful for exact matching when provided accurately.
Retailer SKU
A stock-keeping unit is usually internal to one retailer. It is excellent for locating the same listing or store tag within that retailer, but it should not be assumed to work elsewhere.
ASIN and TCIN
ASIN is Amazon’s catalog identifier; TCIN is Target’s item identifier. Both are retailer-specific. They can anchor a search inside their respective catalogs but require another identifier for dependable cross-retailer matching.
Why multiple identifiers help
One code can be mistyped, reused in a misleading listing or attached to a variant. Matching model, UPC and retailer identifier provides stronger evidence than relying on a product title alone.