Batch numbers/Manufacturing codes are required in most cases and can be found in the following places:
Ergobaby carriers: EBC code found on product label
Tula carriers: Mfg date on the product label
Soft goods: Smallest tag or label on the inside with batch/mfg code
Electrical products: Batch/serial number will be on the base
Trunki suitcases: Date code as clock dials on inside wheel arches
Bath tubs: Dials on base