A diplomatic bag is defined by its role, not its shape
“Bag” is a legal term here, not a size limit. A diplomatic pouch can be a small envelope or a large shipping container, provided it is designated and marked as a diplomatic bag and used to carry official documents or articles for a diplomatic mission. That can make a crate eligible for the same protection as a satchel.
The protection matters because a mission may need to move sensitive government material across borders without allowing customs officials in transit to inspect it. Under diplomatic rules, a diplomatic bag must not be opened or detained. Its unusual size does not, by itself, cancel that safeguard.
The marking establishes the status
A crate does not become a diplomatic bag merely because a government labels its contents important. Its diplomatic status depends on its official designation and external markings, and the protection applies to the bag as a whole. Diplomatic pouches are also normally sealed, so the receiving mission can tell whether the container arrived intact.
That system creates a tradeoff: officials at the border generally cannot check the contents, so the sending government is expected to use the channel for its intended official purpose. The protection is not a general customs exemption for anything a government wants to ship; it is a rule for secure communication and official material between states and their missions.
Why a crate can make sense
The physical container can be matched to the cargo. When official material is too bulky or awkward for ordinary pouches, treating a marked crate as a diplomatic bag lets it travel through the same protected channel. The striking point is that the law’s key question is not whether the container looks like luggage, but whether it has been properly designated for diplomatic use.
