How many times has a client asked you - "Can you send me a format in which I can write requirements? I want to use the format you normally use so that it is easy to understand for your team..." If your experience is similar to mine - scores of times. Sure enough, we send them samples and templates. How many clients came back with a filled in template? None. Why?
Filling in a requirements template is never a straight forward form filling kind of process. Before you even attempt to do so, you spare so much time and effort to understand the background of the project, processes, rules; create many working documents, flowcharts, mockups. When we send a requirements template to client - "You can use this" - we fail to respect the methodology that goes into eliciting and developing requirements.
Switching now to owners of IT projects - if you want to give your developers/IT partners a headstart on requirements, I suggest you do the following instead of trying to fill in any sort of requirements template -
Since a picture is worth thousand words, let me represent my approach with a mindmap -
Send whatever your team comes up with to your Business Analysts / Developers - you have given them a good headstart, they can do the rest!