（Please explain about the identification mark to be marked on multiple overpacks.）
With the 54 Edition, the requirement is mentioned in 22.214.171.124 and with the 55 Edition, this has been relocated to 126.96.36.199 where it says when multiple overpacks are made, to facilitate identification, loading and notification, the operator “requires” each overpack to show an identification mark (in any alpha-numerical format) and the total quantity of dangerous goods, as indicated on the DGD. If there are more than one UN number, the total quantity of dangerous goods must be shown by UN number. The word “requires” is used. Does this imply that this is a mandatory requirement (a “must”) or is it a wish (a “should”)? (30 Nov 13)
The reason why the Overpack paragraphs have been moved from 7.1.4 (54 Edition) to 7.1.7 (55 Edition) is to follow the flow of actual operation. The term “requires” means a “need” for a particular purpose. It must be interpreted as a mandatory requirement (as a “must”).