Roadmaps are usually written as lists of things the team is going to do. Now, next, later. What this format misses, badly, is the equally important list of things the team has decided not to do. Every yes is a no to something else, and an honest roadmap surfaces both. A roadmap without a "no" column is a wish list — it doesn't constrain anything, doesn't force trade-offs, and doesn't actually help anyone make a decision when a new idea shows up.
The "no" column doesn't have to be public-facing. Most useful versions live in an internal Notion doc. But it has to be specific. "We're not going to build a mobile app this year" is a useful no. "We're not building features for enterprise customers right now" is a useful no. "We're not adding third-party integrations until our SSO works" is a useful no. "We're not building a marketplace" — if the team had been quietly assuming a marketplace was coming — is one of the most useful nos you can write.
Putting decisions in the no column has two compounding effects. First, when somebody pitches a new idea (a customer, a board member, an enthusiastic engineer), the answer can be a clear "not now, here's why" instead of a vague "we'll think about it." The vague version pollutes the team's working time forever — people quietly hold the idea in their heads, advocate for it in meetings, build adjacent things to make it easier later. The clear no closes the loop.
Second, the no column makes the yes column more credible. A roadmap that says "yes to everything" is a roadmap with no priorities. A roadmap that says "yes to these three things, and explicitly no to these five other reasonable things" tells the team — and your stakeholders — that real choices were made. The team can execute against that. The stakeholders can plan against it. The next person who pitches the rejected idea gets the version of the answer that contains the reasoning, instead of the version that contains a polite hedge.