Topic: Multiple or Single Requirements Document?

I do like to have workshops to begin the process of requirements gathering. If you have marketing, technical, business, etc. people all in a room then you can usually pull out all of the main requirements. That, of course, is just the start, but you have, at least, the headings and then you can determine how many documents you need (with the default being 1). The document is then written by all the stakeholders in the project as a joint effort. I would normally call this the "Project Requirements" document.

If the project is being developed by more than one supplier (as with a couple of projects I am involved in), then the requirements document is part of the contract with the supplier and usually there will be separate requirements documents for each supplier because of that.