One of the ten big rules of writing a good MRD is writing unambiguous requirements. Ambiguity is a function of communication. The writing can be generically ambiguous, or ambiguous to the writer. A requirement could be precise in intent, but ambiguous in interpretation by the reader. Understanding our audience is as important as precision in language. We write unambiguous requirements because misinterpretation of requirements is the source of 40% of all bugs in delivered software.