What it is
A rental verification form is a structured request sent to a current or former landlord asking them to confirm one tenancy in checkable fields rather than in prose: the dates, the rent amount, any balance owed, the number of late payments, the notices served, and whether they would rent to the tenant again.
It is filled in by the landlord and returned to whoever sent it — a leasing office, a mortgage underwriter documenting rent history, or a public housing agency. Unlike a reference letter it contains no opinion beyond the final question, and unlike a screening report it comes from the landlord's own records rather than from a consumer reporting agency.