1step,rule,n_before,n_after,n_removed,rationale21_field_count,exactly 5 CSV fields (RFC-4180 quoting respected),1200,1164,36,"line cannot be split into the 5 declared columns; content unreadable, not reconstructed"32_sale_id,sale_id matches ^S\d{5}$,1164,1164,0,identifier not in documented format; record cannot be identified unambiguously43_municipality,municipality is one of the 5 control-total municipalities,1164,1164,0,unknown municipality string; not guessed54_sale_date,sale_date is a valid ISO YYYY-MM-DD date,1164,1164,0,date unreadable65_price,"price_cad is a positive integer (plain digits, or a quoted value with standard 3-digit thousands separators)",1164,1164,0,price unreadable or non-positive76_area,area_m2 is a positive decimal number,1164,1164,0,area unreadable or non-positive87_unique_id,sale_id not duplicated among remaining rows,1164,1164,0,duplicate identifiers would be ambiguous9