In setting up an item in AX2012 R3 you can allocate a Standard Transportation commodity Code (STCC) code to the item. STCC codes are a commodity classification code that was largely used by rail transport in north America where it originated. STCC codes are still used by rail companies but has been superseded but SCTG codes as a general classification system for transported goods. You can read more about SCTG on the United State Department of Transportation website. SCTG codes are comparable with SIC and NAICS codes

http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/commodity_flow_survey/html/classification.html

http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/commodity_flow_survey/2002/state_summaries/html/appendix_d.html

http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/commodity_flow_survey/html/hierarchical_features.html

Cheers

Lachlan