There are three aspects: first, the requirements of the developed software, including functional requirements and interface requirements. In general, a demand statement should be attached; The second is the intellectual property rights of software, including copyright, authorship, use right, reproduction right, modification right, publication right, distribution right, lease right, information network communication right, translation right, license right, transfer right and other rights to obtain economic benefits from third-party institutions or individuals. Which side do they belong to? The third is what the after-sales service after development includes, such as training, defect repair, system backup recovery, upgrade and so on.

The first point that should be paid special attention to is that the demand survey of software projects before signing the contract can only get the general development scope, while the accurate and detailed requirements need to be investigated after signing the contract. The workload of demand research is generally greater than coding and testing. However, in order to get the bill as soon as possible, software companies often have no time to do detailed research in the early stage, hoping to complete the project after setting it. There will be a contradiction here: the requirements agreed in the annex to the contract are not detailed, and the results of development according to this contract may be quite different from the expectations of users; If the demand agreed in this contract cannot be met, the developer is worried that the demand will change constantly, resulting in a substantial increase in workload and construction period.

Therefore, sometimes corresponding clauses are added to the contract to explain the control mechanism of demand change.