Do not make personal attacks anywhere in Wikipedia. Comment on content, not on the contributor. Personal attacks will rarely help you make a point; they hurt the Wikipedia community and deter users from helping create a good encyclopedia.
Don't do it Edit
There is no excuse for personal attacks on other contributors. Do not make them.
Remember that disputes on talk pages are accessible to everyone on the Internet. The way in which you conduct yourself on Wikipedia reflects on Wikipedia and on you.
Many Wikipedians remove personal attacks on third parties on sight, and although this isn't policy it's often seen as an appropriate reaction to extreme personal abuse. Users have been banned for repeatedly engaging in personal attacks. Abusive edit summaries are particularly ill-regarded.
Being reasonable Edit
Different contributors may not agree on an article. Members of opposing communities reasonably wish to express their views. Synthesising these views into a single article creates a better, more NPOV article for everyone. Remember to accept that we are all part of the same community as we are all Wikipedians.
Specific examples of personal attacks include but are not limited to:
- Accusatory comments such as "Bob is a troll", or "Jane is a bad editor" can be considered personal attacks if said repeatedly, in bad faith, or with sufficient venom.
- Negative personal comments and "I'm better than you" attacks, such as "You have no life."
- Racial, sexual, homophobic, ageist, religious or ethnic epithets directed against another contributor. (Disagreement over what constitutes a religion, race, sexual preference, or ethnicity is not a legitimate excuse.)
- Using someone's affiliations as a means of dismissing or discrediting their views — regardless of whether said affiliations are mainstream or extreme.
- Profanity directed against another contributor.
- Threats of legal action.
- Threats of violence, including death threats.
- Threats or actions which expose other Wikipedia editors to political, religious or other persecution by government, their employer or any others. Violations of this sort may result in a block for an extended period of time which may be applied immediately by any sysop upon discovery. Sysops applying such sanctions should confidentially notify the members of the Wikipedia:Arbitration Committee and Jimbo Wales of what they have done and why.
- Posting a link to an external source that fits the commonly-accepted threshold for a personal attack, in a manner that incorporates the substance of that attack into Wikipedia discussion. Suggesting a link applies to another editor, or that another editor needs to visit a certain link, that contains the substance of an attack.
Examples that are not personal attacks Edit
Wikipedians engaging in debate is an essential part of the culture of Wikipedia. Be civil and adhere to good wiki etiquette when stating disagreements to avoid personalizing them and try to minimize unnecessarily antagonistic comments. Disagreements with other editors can be discussed without resorting to personal attacks. It is important not to personalize comments that are directed at content and actions, but it is equally important not to interpret such comments as personal attacks. Specific examples of comments that are not personal attacks include, but are not limited to:
- Disagreements about content such as "Your statement about X is wrong" or "Your statement is a point of view, not fact" are not personal attacks.
- Personal attacks do not include civil language used to describe an editor's actions, and when made without involving their personal character, should not be construed as personal attacks. Stating "Your statement is a personal attack..." is not itself a personal attack — it is a statement regarding the actions of the user, not a statement about the user. There is a difference between "You are a troll" and "You are acting like a troll", but "You seem to be making statements just to provoke people" is even better, as it means the same without descending to name-calling. Similarly, a comment such as "responding to accusation of bad faith by user X" in an edit summary or on a talk page is not a personal attack against user X.
- A comment in an edit history such as "reverting vandalism" is not a personal attack. However, it is important to assume good faith when making such a comment — if the edit that is being reverted could be interpreted as a good-faith edit, then don't label it as vandalism.
- Discuss the facts and how to express them, not the attributes of the other party. This does not mean that you have to agree with the other person, but just agree to disagree.
- Never suggest a view is invalid simply because of who its proponent is.
- Explore issues in a less public forum like e-mail if a debate threatens to become personal.
- Read Wikipedia:Resolving disputes.
If you are personally attacked, you should ask the attacker to stop and note this policy. If he or she continues, consider following the dispute resolution process. You might also consider removing particularly clear-cut personal attacks per the guideline WP:RPA; however, you should be very careful not to define "personally attack" too broadly, or to do this too frequently. From a recent arbitration committee finding-of-fact:
- The remove personal attacks guideline (and the application thereof) is controversial. It has often been abused by malefactors, and may not have community consensus. It should, at most, be interpreted strictly and used sparingly. 
If you find yourself using this remedy frequently, you should reconsider your definition of "personal attack." When in doubt, follow the dispute resolution process instead.
In extreme cases, an attacker may be blocked under the "disruption" clause of the blocking policy, though the practice is almost always controversial. Personal attacks should be reported at WP:PAIN.
A misguided notion: "Kicking them while they are down" Edit
Note: There are certain Wikipedia users who are unpopular, perhaps because of foolish or boorish behavior in the past. Such users may have been subject to disciplinary actions by the Arbitration Committee. It is only human to imagine that such users might be fair game for personal attacks. This notion is misguided; people make mistakes, often learn from them and change their ways. The NPA rule applies to all users irrespective of their past history or how others regard them.
It is your responsibility to foster and maintain a positive online community in Wikipedia. Personal attacks against any user - regardless of his/her past behavior - are contrary to this spirit.
Off-wiki personal attacksEdit
As with the attacks defined above, personal attacks on other editors in off-Wikipedia venues reflect badly on the attacker and are unlikely to achieve a positive outcome. Wikipedia acknowledges that it cannot regulate behavior in media not under the control of the Wikimedia Foundation, but personal attacks elsewhere may create doubt as to whether your on-wiki actions are being conducted in good faith. Posting personal attacks or defamation off-Wikipedia is harmful to the entire community, and to your relationship to it.
Whilst you may not be directly penalised for off-wiki attacks, they may be taken as aggrevating factors when any on-wiki policy violations are being considered. For example, they can be used as evidence of bad faith in the dispute-resolution process, or as evidence in an ArbCom decision.
See also Edit