There is a wide diversity of structures and purposes in the NPO landscape. For legal classification and eventual scrutiny, there are, nevertheless, some structural elements of prime legal importance:

• Economic activity
• Supervision and management provisions
• Representation
• Accountability and Auditing provisions
• Provisions for the amendment of the statutes or articles of incorporation
• Provisions for the dissolution of the entity
• Tax status of corporate and private donors
• Tax status of the foundation

Some of the above must be, in most jurisdictions, expressed in the document of establishment. Others may be provided by the supervising authority at each particular jurisdiction.

While affiliations will not affect a legal status, they may be taken into consideration in legal proceedings as an indication of purpose.

Most countries have laws which regulate the establishment and management of NPOs, and which require compliance with corporate governance regimes. Most larger organizations are required to publish their financial reports detailing their income and expenditure for the public. In many aspects they are similar to business entities though there are often significant differences. Both non-profit and for-profit entities must have board members, steering committee members, or trustees who owe the organization a fiduciary duty of loyalty and trust. A notable exception to this involves churches, which are often not required to disclose finances to anyone, including church members, though most churches remain fiscally transparent with their members.

http://en.wikipedia.org/wiki/Non-profit_organization#Legal_aspects