Rename classification_effective_dates.csv to data/raw/industry_codes_NAICS/classification_effective_dates.csv
3ff1f1e verified | System_Name,Effective_Date,Notes | |
| NAICS 2022,2022-01-01,Current active standard (as of 2022). | |
| NAICS 2017,2017-01-01,Replaced by 2022 revision. | |
| NAICS 2012,2012-01-01,Replaced by 2017 revision. | |
| SIC 1987,1987-01-01,Replaced by NAICS in 1997 but widely used for historical continuity. | |