See ASTM A700
Standard Practices for Packaging, Marking, and Loading Methods for Steel Products for Domestic Shipment
1,
5.3 Marking:
5.3.1 It is normal practice to stamp or paint the heat number
on each piece shipped loose and to show the heat number on a
tag attached to each secured lift of smaller size billets. The
ordered size and weight may be painted on at least one piece of
each size when shipped loose or on at least one piece of each
secured lift. Each skelp coil is tagged or marked with the heat
number and the size.
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Each plate has its identification number
Regards