The contents of Notes 1 to DGR 188.8.131.52,2 Step 7 is identical to the Note following DGR 184.108.40.206 that for multiple overpacks, an identification number for the overpack and the quantity of dangerous goods must be shown by UN number. Let me answer your question. First of all, the meaning on “one consignment” is “one straight AWB” or in the case of a consolidation, “one House AWB”. It does not refer to a Master AWB.
If a consignment carries two dangerous goods (for example, UN xxxx and UN yyyy), and they are each packed in separate overpacks, an identification mark is needed for the 2 overpacks, i.e., Overpack No. 1 and Overpack No. 2. The UN number is to identify the dangerous substance or the dangerous article. The purpose of identification is different.
Overpack No. 1 would show UN xxxx, the Proper Shipping Name and the quantity, and Overpack No. 2 would show UN yyyy, the Proper Shipping Name and the quantity. A check is made against the Declaration.
You are mixing the identification mark on the overpack and the UN number, the latter is to identify the dangerous goods. The manner you are taking is a short cut of the acceptance procedure which is strictly prohibited in the handling of dangerous goods. You must clearly differentiate the purpose of the marks and/or numbers and the aim of the check. Shortcuts must never be employed in the process of dangerous goods. A step by step check is mandatory commensurate with its purpose.