A business plan is a formal statement of business goals, reasons they are attainable, and plans for reaching them. It may also contain background information about the organization or team attempting to reach those goals.
External stake-holders of non-profits include donors and the clients of the non-profit's services. For government agencies, external stakeholders include tax-payers, higher-level government agencies, and international lending bodies such as the International Monetary Fund, the World Bank, various economic agencies of the United Nations, and development banks.
Non disclosure agreements (NDAs) with third parties, non-compete agreements, conflicts of interest, privacy concerns, and the protection of one's trade secrets may severely limit the audience to which one might show the business plan. Alternatively, they may require each party receiving the business plan to sign a contract accepting special clauses and conditions.
It also needs to be written in formal format and style. You have to remember that a business plan is something that you may have to present to your business partners, financial firms and banks. So if you can, refrain from using slang in any part of your plan.