4.2 Location, size, and content. Whenever practicable,
the location of the marking on the item shall ensure its visibility during
normal operational use of the item. Marking size shall satisfy the legibility
requirements of 4.5.
4.2.1 Serialized items. Any item
that is serialized shall include the minimum set of data elements necessary
to provide unique identification (UID) (see 6.4.1). Methods
of UID construction are determined by the manufacturer’s serialization
protocol (see Table 3).
a. Construct #1 – enterprise identifier and a serial number
unique within the assigning activity (see figures 2.a and 2.b), or
Construct #2 – enterprise identifier, part number and a serial number unique
within the product identified (see figures 2.c and 2.d)