(a) In representing a client, a lawyer shall not use means that have no substantial purpose other than to embarrass, delay, or burden a third person, or use methods of obtaining evidence that violate the legal rights of such a person.
(b) A lawyer who receives a document relating to the representation of the lawyer's client and knows or reasonably should know that the document was inadvertently sent shall promptly notify the sender.
[Originally effective September 1, 1985; amended effective September 1, 2006.]
 Responsibility to a client requires a lawyer to subordinate the interests of others to those of the client, but that responsibility does not imply that a lawyer may disregard the rights of third persons. It is impractical to catalogue all such rights, but they include legal restrictions on methods of obtaining evidence from third persons and unwarranted intrusions into privileged relationships, such as the client-lawyer relationship.
 Paragraph (b) recognizes that lawyers sometimes receive documents that were mistakenly sent or produced by opposing parties or their lawyers. If a lawyer knows or reasonably should know that such a document was sent inadvertently, then this Rule requires the lawyer to promptly notify the sender in order to permit that person to take protective measures. Whether the lawyer is required to take additional steps, such as returning the original document, is a matter of law beyond the scope of these Rules, as is the question of whether the privileged status of a document has been waived. Similarly, this Rule does not address the legal duties of a lawyer who receives a document that the lawyer knows or reasonably should know may have been wrongfully obtained by the sending person. For purposes of this Rule, "document" includes e-mail or other electronic modes of transmission subject to being read or put into readable form.
 Some lawyers may choose to return a document unread, for example, when the lawyer learns before receiving the document that it was inadvertently sent to the wrong address. Where a lawyer is not required by applicable law to do so, the decision to voluntarily return such a document is a matter of professional judgment ordinarily reserved to the lawyer. See Rules 1.2 and 1.4. [Comments adopted effective September 1, 2006.]
Additional Washington Comments [4-5]
 The duty imposed by paragraph (a) of this Rule includes a lawyer's assertion or inquiry about a third person's immigration status when the lawyer's purpose is to intimidate, coerce, or obstruct that person from participating in a civil matter. Issues involving immigration status carry a significant danger of interfering with the proper functioning of the justice system. See Salas v. Hi-Tech Erectors, 168 Wn.2d 664, 230 P.3d 583 (2010). When a lawyer is representing a client in a civil matter, a lawyer's communication to a party or a witness that the lawyer will report that person to immigration authorities, or a lawyer's report of that person to immigration authorities, furthers no substantial purpose of the civil adjudicative system if the lawyer's purpose is to intimidate, coerce, or obstruct that person. A communication in violation of this Rule can also occur by an implied assertion that is the equivalent of an express assertion prohibited by paragraph (a). See also Rules 8.4(b) (prohibiting criminal acts that reflect adversely on a lawyer's honesty, trustworthiness, or fitness as a lawyer in other respects), 8.4(d) (prohibiting conduct prejudicial to the administration of justice), and 8.4(h) (prohibiting conduct that is prejudicial to the administration of justice toward judges, lawyers, LLLTs, other parties, witnesses, jurors, or court personnel or officers, that a reasonable person would interpret as manifesting prejudice or bias on the basis of sex, race, age, creed, religion, color, national origin, disability, sexual orientation, or marital status). [Comment  adopted effective August 20, 2013.]
 A risk of unwarranted intrusion into a privileged relationship may arise when a lawyer deals with a person who is assisted by an LLLT. Although a lawyer may communicate directly with a person who is assisted by an LLLT, see Rule 4.2 Comment , client-LLLT communications are privileged to the same extent as client-lawyer communications. See APR 28K(3). An LLLT's ethical duty of confidentiality further protects the LLLT client's right to confidentiality in that professional relationship, see LLLT RPC 1.6(a). When dealing with a person who is assisted by an LLLT, a lawyer must respect these legal rights that protect the client-LLLT relationship. [Comment  adopted effective April 14, 2015.]