Because the WordPress community is global, it’s important to remember that everyone has different circumstances, knowledge, and levels of experience. As a general rule, all written communication should be clear and friendly, with a tone that’s on the positive side of neutral.
Language choice is important since most communication is in text and English. Staying relatively jargon-free helps people who are speaking English as a second language as well as any new or inexperienced contributors. Leaders especially should remember that anything you write could be someone’s first introduction to the project and how we treat each other.