This means that you'll be able to search for NAICS codes directly (if that's your jam). We'll do the math; let's make better data on public procurement together.
Real Property Appraisals Services (SIC 6531)
Possible NAICS Codes
531320 – Offices of Real Estate Appraisers
531210 – Offices of Real Estate Agents and Brokers
541191 – Title Abstract and Settlement Offices