Open Issues

When you first write the functional specification, there will be one or two (thousand) things you don't know. That's okay. Just put them in the “Open Issues” section. Then every time you meet with the customer, point to this section and try to get answers. Some of these questions will move to requirements sections and some will end up in the “Non-requirements” section, after you get those answers. By the end of the project, though, this section should be empty. If it's not, well, you've got issues that will haunt you.