I have seen some grammar advice that suggests one should capitalise the name of a document even if the name is also a description of the document. For example, if I am writing a business plan and the title of the document written on the front page is "Business Plan", I should refer to the document as the Business Plan rather than the business plan. What are people's views on this?
Does the need to capitalise change if we are referring to the document in the plural. For example if I was to refer to multiple business plans, would it be correct to call them the Business Plans? Capitalisation seems somewhat more unusual for plurals.
Does the need for capitalisation change if I refer to them using the indefinite article? For example, would it be correct to say "a Business Plan".
What would the rules for capitalisation be if the document is saved with the file name "Plan for Business Growth", but the title on the front page of the document is "Business Development Plan 224"? Are both of these proper nouns or only the latter?
I am seeking advice in relation to general usage, not in relation to any specialist usage.