Where the format rules come from
The plate series catalog — names, fixed prefixes, plate number formats, and who may request each series — is sourced from the current Massachusetts RMV Passenger Plates Manual, kept dated, and versioned whenever it changes. Where the manual only shows examples rather than a stated rule, we say so: every series carries a confidence label like confirmed or manual examples only, and nothing is promoted past what its source supports.
What "taken", "likely open", and "unknown" mean
- Taken — a current record shows the plate number attached to a registration (including suspended or revoked plates, which are still not requestable).
- Likely open — the most recent reliable observation found the plate number unheld (cancelled, expired, or confirmed not found). We always show the observation date, and we always say: confirm with the RMV before counting on it.
- Unknown — our records have no reliable answer. Our database is a curated collection of observations, nowhere near every plate Massachusetts has issued, so absence from our records is not evidence of availability.
We never claim a plate is guaranteed available to register. Only the RMV can tell you that, at the moment you apply.
Data freshness
Plate records carry the date they were last observed, and every availability label shows its date. The Low Plate Board shows the snapshot date of its most recent review. If a date looks old, treat the answer as old.
What the Idea Finder will never suggest
Series that are closed to new requests — renew-only plates, lottery-allocated low numbers, office-of-holder plates — are never searched, even if you edit the URL by hand. Series with a real eligibility gate (veteran plates, medical plates, and similar) only appear when you explicitly opt in via the advanced series filter, with the manual's own eligibility wording shown beside them.
Independence
MAPlates is an independent project. It is not affiliated with, endorsed by, or connected to the Massachusetts Registry of Motor Vehicles. Plate imagery is stylized for preview purposes.