For reference material on barcodes refer to the following documents:
Find out who owns a barcode here:
http://gepir.gs1.org/v32/xx/gtin.aspx?Lang=en-US
The actual ISO standard for barcode testing:
http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=27659
GS1’s guide for barcodes (and other things). Section 5 & 6 are of most relevance:
http://www.gs1.org/docs/barcodes/GS1_General_Specifications.pdf
GS1’s guides for setting up a barcode verification process, which you can use in your own company:
http://www.gs1.se/globalassets/gs1-bar-code-verification.pdf
http://www.gs1.org/docs/barcodes/GS1_Operational_Guidance_Bar_Code_Verification.pdf
http://www.gs1.org/docs/barcodes/1D_Barcode_verification_implementation_guideline.pdf
Handy layman’s summaries of the technical aspects of barcode verification:
https://www.bar-code.com/verifiers/LaymansGuidetoANSI.pdf
http://www.barcode-test.com/wp-content/uploads/2013/08/Getting-it-Right-2nd-Release-June-2013.pdf
http://c.ymcdn.com/sites/www.aimglobal.org/resource/resmgr/docs/tsc-04-028-laymananisisocen_.pdf
If you need local support, please refer to Intermax at http://www.barcodeverification.com.au