Open Source communities are sometimes seen as hostile, for all sorts of reasons ranging from "too much email" to "they're not being nice with me". It mostly works however, and the Apache Software Foundation, which we'll use as the basis for our examples, is a living testimony to that: more than twenty years of successful collaboration among people from different cultures, age groups, professional backgrounds and other reasons for disagreeing. It's not always smooth, however, and finding flaws in our communications styles and mechanisms is easy if you look a bit closer. In this talk, instead of looking for flaws, we will focus on what works in terms of online communications in such semi-chaotic environments. Conciseness and clarity are key in avoiding misunderstandings, but they can be hard to achieve. To help with that, we will present concrete examples based on well-known techniques like precise quoting, radiating intent, reformulating, following Blaise Pascal's advice, assuming good intentions and other simple principles that make all the difference. This talk, based on more than twenty years of experience with multiple Open Source projects and communities, will help you improve your online communications, with the goal of reducing hostility and misunderstandings. Concise and clear wins over verbose and foggy, every time!