It seems to have been put there to fill the need to attribute a certain sum to marketing. Make sure you are researching each point of your budget, make sure that you are giving it context and it makes proper sense within your overall plan.
The business plan serves several purposes: Enables the entrepreneur to think through the business in a logical and structured way and to set out the stage in the achievement of the business objectives ; Enables the entrepreneur to plot progress against the plan ; Ensures that the resources needed to carry out the strategy and the times when they are required are both identified ; Preparing the business plan ensures that the entrepreneur has thought through the crucial aspects of the venture ; It is a means for making all employees aware of the business direction ; It is an important document for discussion with prospective investors and lenders of finance ; It links into the derailed, short-term, one-year budget.
So it is crucial that every time you mention financials in your business plan, to really give them the correct context. When I have worked with clients in developing business plans, there has been a budget or amount set aside for example to be spent on marketing, which has been decided a bit arbitrarily. I mean with no real research, no understanding of what that amount needs to be spent on, and what that budget will truly achieve.
Before the preparing the plan, the entrepreneur should: Review previous business plans (if any) and their outcome. This review will help highlight which areas of the business have proved difficult to forecast historically. Be very clear as to objectives on which their plans will be based. Set out the key business assumptions on which their plans will be based.