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400 - Duplicate References
The error code
duplicate_references is returned when a collection of references includes 2 or more duplicates. Shipments API will not attempt to de-dupe incoming values, because our aim is to make sure that operations are explicit rather than implicit.This error code will be returned, for example, if you attempt to make an API call to an allocate endpoint and provide the same shipment reference more than once in the payload:
{
"shipments": [
"sp_10014418679662051328667654221112",
"sp_10014418679662051328667654221112"
]
}