In the brokering world, it is common for parties to document their commission/fee requirements within irrevocable fee protection agreements (IMFPA). It is also common a common belief that these fee agreements need to have a "buyside" and a "sellside" to them. It is true that the architecture of many of these document are configured contain areas of the document that lists the wiring coordinates and instructions for each of these parties within a "box" which is often formatted as a "table" within Microsoft Word. It is common to see one box for a sellside group and three boxes on the buyside.

Is there any law that says there has to be a buyside and a sellside? No.

Is there any law that says there needs to be one box on the sellside and three boxes on the buyside? Absolutely not.

Fee agreements can be configured in unlimited configurations by anybody that has competent custom document skills. It's completely limited to the architectural skills of the document's creator. 

Notice that the skillsets of most brokers are fairly limited to being laser-like focused on engineering boxes for themselves on a fee agreement, writing "OPEN" and "CLOSED" on various "boxes" within the fee agreement, and highlighting words with various colors that aggravate even most kindergartners today. The formatting and language of these broker documents typically look like kids assembled them and do not resemble the professionalism that is often required to have demand such commissions to be respected.

In the opinion of Magister Operis™... due to the enormous typical waste of energy that average brokers/intermediaries expend towards inventing buysides and sellsides for themselves... whoever invented the "buyside" and the "sellside" of brokering/intermediary transactions was not thinking clearly.

Consider the fact that neither the buyside nor the sellside of anything even matters if neither side can professionally outline what makes their side of a deal real... much less make both sides of a deal intelligently real.