Training and communicating to employees and contractors the rules of conduct to prevent and eliminate the potential for harassment, discrimination, hostility and other forms of unlawful and otherwise undesirable behavior in the work environment is complicated, time consuming and absolutely essential. Having said that, there is a simple way for most reasonable people to get an initial sense or "gut check" on whether a particular verbal or physical communication from or to a fellow worker is appropriate:
If you said it or did it in front of one of several authority figures or significant others in your life (family member, boss, Human Resources person, etc.) would you be embarrassed or concerned? If the answer is "yes", it doesn't necessarily mean it is unlawful or even offensive to most people by itself, but it raises a red flag that it doesn't belong in a healthy workplace and shouldn't be acceptable. Even persistent insensitivity can grow like a cancer in your corporate culture and breed unhealthy - and eventually unlawful - behavior.