The Golden Rule of Netiquette is to do unto others online as you would have done to you online. This is the spiritual foundation of netiquette and recurring motif in the Catholic religion.
Please be advised that the Golden Rule of Netiquette is the only a spiritual basis for how to interact with people online. It is not to be taken literally because it is always bad netiquette to flame even if it does not bother you when others flame you. The Golden Rule of Netiquette is a call to consciousness rather than a call to a particular action.
Technically, there are three separate definitions of netiquette. Each definition is separate and distinct, as well as adding dimensions that the others do not have.