Do not make jokes or unfriendly remarks about race, ethnic origin, skin color, gender, or sexual orientation.
Use inclusive language. For example, prefer “Hi everybody” or “Hi people” to “Hi guys”.
Share problems you run into, ask for help, be forthcoming with information and speak up.
Don’t display surprise when people say they don’t know something, as it is important that everyone feels comfortable saying “I don’t know” and “I don’t understand.” (As inspired by Recurse.)
You can always refuse to deal with people who treat you badly and get out of situations that make you feel uncomfortable.
Always be kind.
Everyone can remind anyone in the company about these guidelines. If there is a disagreement about the interpretations, the discussion can be escalated to more people within the company without repercussions. If you are unhappy with anything (your duties, your colleague, your boss, your salary, your location, your computer) please let your boss, or the CEO, know as soon as you realize it. We want to solve problems while they are small.
Make a conscious effort to recognize the constraints of others within the team. For example, sales is hard because you are dependent on another organization, and Development is hard because you have to preserve the ability to quickly improve the product in the future.