baseline
A specification or product that has been formally reviewed and agreed upon, that thereafter serves as the basis for further development and that can be changed only through formal change control procedures.
Baselines provide a snapshot of the aggregate of system components as they exist at a given point in time. They are typically used by management to establish system integrity at the end of each phase of the system life cycle.
For example, at the completion of design you establish a design baseline. The baseline consists of all documents that will act as a reference for code development and testing. At this point you ensure that components of this baseline cannot be changed without formal approval and notification of affected programmers. In this way you will ensure that programmers do not write code to designs that have changed.