Public information disclosure by startups that are still private?

Forming an entity (e.g., a corporation or LLC) will generally require you to disclose, to the jurisdiction in which the entity is being formed, the principal physical location of the business, and name and location of the registered agent. Whether the organizer, board members, members / managers, or other individuals (and their locations) need to be identified varies jurisdiction to jurisdiction and different jurisdiction make different information publicly available online. Some jurisdictions require you to disclose corporate capitalization (but I cannot think of one which makes that information publicly available). If your startup needs certain business licenses, you may need to disclose personnel information to responsible municipal or county agencies. You may, upon selling securities, need to file forms with the SEC or state agencies in which you disclose certain financial details. Some jurisdictions (e.g., Nevada) try to attract foreign entities by lauding the privacy they afford to business organizers. However, "privacy" interests should be taking a back seat to logistical, tax, and other considerations to make when going into business.