This block of information is a datamatrix. The QR Reader App can read datamatrix codes.
Using Wingspar’s example from his 7/1/2017 thread referenced earlier, the app produces:
[)>0617V553581P3005932SNAV28XX (last two digits changed to X for privacy).
Indeed, the unobscured beginning of his serial number shown next to the datamatrix on his gun begins NAV28____ which matches the latter part of the numeric code.
However, there appear to be two or possibly three other sets of numbers that may include manufacture location, date and very specific version/model numbers.
Two 1 Gen 9mm Shields of mine have datamatrix codes:
[)>0617V553581P423630000SHDD35XX
[)>0617V553581P423630000SHLL91XX
And a Gen 1 FS M&P 9mm FDE:
[)>RS06GS17V553581P396960000S HNH89XX RSEOT (Serial # separated by me) Manf date from box = 052516
Note the similarities/dissimilarities in certain groups of all three of these numbers. There is more going on there than just a serial number, despite what S&W CS represented. Some of these sets of numbers are different than those on the box labels and their corresponding bar codes. Serial # and bar codes are of course the same.