Registered FDA device establishments whose firm name contains what the filer has typed so far (typeahead), for the DEV and DFE affirmations. A filer types the manufacturer or exporter named on the device and accepts a match to fill in the registration number, which they would otherwise have to obtain from that firm. filter.role picks which party the question names, and filter.productCode (the line's FDA product code) narrows a large firm's many registered sites to the ones that actually list this device. Matching is substring and case-insensitive; returns empty for a term shorter than two characters.