MOD-IV
New Jersey's standardized local property-tax assessment data format used to transmit municipal assessment-roll information.
New Jersey example
Parcel assessment, class, tax and many physical fields in Watchdog originate from MOD-IV-based public records.
Official source
https://www.nj.gov/treasury/taxation/lpt/localtax.shtml
This is a plain-English summary. Rules and dollar amounts change, so check the official source or a professional before you file or sign anything.