I would like to add new fields to places in Google Maps, and use them in my application. These fields may be contributed by users or annotators. These fields may eventually be visible to the public - this is TBD.
For example, when there is a non-profit listed in the map, I'd like to add a Google Maps tag called EIN showing its Employer Identification Number - which is available in public tax returns.
I searched in a few Google Maps documents and forums - no luck so far. It seems user contribution of new places was deprecated in 2018.