Traditionally business plans have been highly confidential and quite limited in audience. The business plan itself is generally regarded as secret. An open business plan is a business plan with unlimited audience. The business plan is typically web published and made available to all. In the free software and open source business model, trade secrets, copyright and patents can no longer be used as effective locking mechanisms to provide sustainable advantages to a particular business and therefore a secret business plan is less relevant in those models.
Business plans may be internally or externally focused. Externally focused plans target goals that are important to external stakeholders, particularly financial stakeholders. They typically have detailed information about the organization or team attempting to reach the goals. With for-profit entities, external stakeholders include investors and customers.
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.
Starting up a business is an exciting time, but writing a business plan can seem daunting initially. However, being able to write a good business plan is an essential skill to have for any entrepreneur or new business looking to increase their chance of survival.