I've been spending quite a bit of time with NAICS Codes lately so thought I'd throw in my two cents worth.
We code loans with NAICS Codes, but for our own purposes we "drilled" down further into the way we code these loans, primarily directed at CRE loans and those that are owner/investor rather than owner-occupied. We have alot of loans in the NAICS Code "Real Estate, Rental and Leasing" Category. Rather than just use the R/E, Rental & Leasing category we reviewed the loan to determine repayment source. We deemed it helped us more to have that loan with an NAICS code of Food Service rather than a basic R/E, R, L code if the building was soley leased as a pizza parlour. Those that were apartment complexes or totally mixed-use strip centers stay at R/E, R, L code.
We also don't loose track that these are R/E, R, L as we can determine that from the Owner/Investor occupancy code on the loan.
Along with the loan type, call report code and collateral code.