MoSCoW

Prioritization technique for managing requirements.

Snippet from Wikipedia: MoSCoW method

The MoSCoW method is a prioritization technique used in management, business analysis, project management, and software development to reach a common understanding with stakeholders on the importance they place on the delivery of each requirement; it is also known as MoSCoW prioritization or MoSCoW analysis.

The term MoSCoW itself is an acronym derived from the first letter of each of four prioritization categories (Must have, Should have, Could have, and Won't have), with the interstitial Os added to make the word pronounceable. While the Os are usually in lower-case to indicate that they do not stand for anything, the all-capitals MOSCOW is also used.