The data is submitted in the description field of the note, but in a predefined format e.g.:
onosm.org submitted note from a business: name: MongoDB Inc phone: +44 870 495 8023 website: http://mongodb.com/ twitter: @mongodb hours: Mo-Fr 10:00-18:00 category: Tech Startups address: Unit 1E, Zetland House, 5-25 Scrutton Street, London
A comment on using notes for this
For the most part this seems like a useful kind of note to add, although sometimes business listings aren't really the kind of thing we would add to OSM. Also asking a user to input structured fields, perhaps it is time to make them aware of editors and tags and things (Notes are designed really for unstructured free-form text input). On the whole though, this seems quite good, and not in violation of any Notes#Notes API guidelines.
Developed by User:Yellowbkpk.
Code is on github: https://github.com/osmlab/onosm.org