Connecticut, IRS, and HAS rules
In the general scheme of rules, a corporation is created in Connecticut when a ‘Certificate of Incorporation’ is issued by the state. It binds the corporation to all of the state laws on corporations as interpreted by the Courts. That makes it very difficult to understand the rules, so every few years the Secretary of State issues the ‘Connecticut Revised Nonstock Corporation Act’ which provides guidance but it still subject to Court interpretation.
Operating beneath these two documents is a set of rules, we call the bylaws, written by the corporation and filed with the Secretary of State and IRS. The bylaws cannot change or override the 'Certificate of Incorporation'. It must be changed with the State. Although the bylaws contain a Purpose, the actual Purpose is in the ‘Certificate of Incorporation’.
The IRS has a process where an existing corporation can apply a 501(C)(3) status to become a nonprofit for federal income tax purposes. If the application is successful a determination lettter is issued to the organization. The application and letter is available on this page. Help is available in IRS Publication 557, Tax-Exempt Status for Your Organization.
The State now accepts the federal nonprofit status for state purposes. However, state applications regarding excise and sales taxes must still be completed.
Lastly, after the State accepts the federal status, the organization must apply for tax exempt status to each town where it owns property.