The BarCode area of PDF::API2 already creates a number of bar codes. I need to print out examples of each, to tell for sure, but I think they are all (or mostly) "one dimensional" bar codes. PDF::API2 needs some "2D" barcodes (look like badly pixelated images) and QR codes (those funky square things you scan with a smartphone). Preference would be given to standalone libraries (not requiring a dependency on other libraries), but where that would involve a ridiculous amount of code to be added to PDF::API2, a glue interface to another (existing and currently supported) CPAN module would be acceptable.
Depending on how many flavors of 2D and QR codes we might end up supporting, we should think about the organization up font. If there are enough, there could be BarCode2D/ and QRCode/ directories as siblings of Resource/XObject/Form/BarCode/.
And of course, additional "1D" barcodes are always welcome, so long as they are in reasonably wide use. No "company-proprietary" or experimental/one-off codes, please.