This tag is attached to a Dana axle with 4.63:1 ratio.   The bill of material number is also found on this tag.  The BOM number is V605807-1.
The tag is located on the edge of the differential cover.

This tag is attached to a Ford 8.8 axle with a 3.55:1 ratio.
It is attached with a bolt on the differential cover.

These numbers are located on a Dana ring gear.   These numbers tell you what ratio your axle is, the manufacturer's part number for the ring gear, and the date of manufacture.  Similar numbers can also be found on most other manufacturer's ring gears.