Profile :: What is atheism?
The word "atheism" represents an all-encompassing and tremendously diverse classification-demographic of individuals who share one specific trait -- the absence of belief in any deities (gods and goddesses). All other traits are incidental.
While some atheists are more outspoken than others (some are also anti-theistic), these are individual traits that are incidental to atheism, hence there is no specific expectation to conform to any particular standards of behaviour. And one of the most important reasons for this is that there exists no "atheist doctrine" (atheism is not in any way dogmatic).