Chief Justice BENDER
delivered the Opinion of the Court.
T1 This original proceeding brought under C.A.R. 21 arises from a divorce and parenting case that is in its third year of post-dissolution decree litigation. Mothers petition challenges the district courts summary denial of her motion for a protective order and sanctions concerning the acquisition by Fathers attorney of Mothers entire employment file from Mothers former employer by subpoena. We accepted jurisdiction to determine whether Fathers attorney violated C.R.C.P. 45 when she made arrangements with Mothers former employer for the production of Mothers employment file without Mothers consent and before Mother had notice of the existence of the subpoena.
T2 We interpret Rule 45 to require that, unless the subpoenaed witness and other parties consent to an alternate arrangement or by other court order, subpoenaed documents are to be produced only at the deposition, hearing, or trial specified in the subpoena and hold that the conduct of Fathers attorney in this case violated Rule 45. We further hold that because Rule 45 sets forth the procedure for the fair marshaling of subpoenaed testimony and documents, Fathers attorney frustrated the purpose of Rule 45 by depriving Mother of the opportunity to object to the subpoena before the documents were produced. Although the personal and sensitive nature of the documents obtained by Fathers attorney magnifies her violation of Rule 45, our holding is not dependent on the documents being privileged, confidential, or otherwise protected. Thus, we need not reach the question of whether an employment file is presumed to be protected from discovery.
T3 For these reasons, we reverse the trial courts order, make the rule absolite, and remand this matter to the trial court. On remand, we direct the trial court to ensure that Father and Fathers attorney identify and recover, and then return or destroy all physical and electronic copies of the doeu-ments produced by Mothers former employer pursuant to the subpoena issued by Fathers attorney, including Mothers entire employment file We also direct the trial court to determine whether sanctions should be awarded to Mother against Fathers attorney for the rule violation.
I. Facts and Proceedings Below
T 4 There is no dispute between the parties as to the facts or sequence of events germane to this appeal. Jeffrey Wiggins (Father) and Zwilda Wiggins (Mother) were divorced in May 2009. Since then, the parties have been embroiled in post-dissolution decree litigation. Both parties sought discovery in advance of an October 18, 2011 hearing concerning parenting time and child support.
{5 Three business days before the October 13 hearing, Fathers attorney served a subpoena on an individual who worked at the school where Mother was previously employed. When the schools office manager called Fathers attorneys law firm to inform Fathers attorney that the individual was out of the office for two weeks, Fathers attorney served a second subpoena a couple of hours later. This time, the subpoena was served on the schools office manager. The subpoena commanded the office manager to appear at the October 18 hearing and to produce, at the hearing, Mothers entire employment file, as well as any other records of communications with Mother:
You are hereby ordered to attend and give testimony at the Douglas County District Court ... on Thursday, October 13, 2011, at 1:30 p.m. as a witness for the Petitioner [Father] and also to produce then and there the documents listed in the attached Exhibit A now in your custody and control."
Exhibit A
Produce the entire [school] employment file for Ms. Wiggins, as well as any and all records of correspondence with Ms. Wiggins throughout her employment at [the school], including any written letters, notes from phone conversations, and notes from in-person meetings.
(Emphasis added.)
T6 Approximately ten minutes after the schools office manager had been served with the subpoena, a third individual-the schools business manager-called Fathers attorney and left a voice message informing her that the schools office manager was not authorized to access or verify the schools personnel files. When Fathers attorney returned the business managers call, the business manager further explained that the schools personnel files were kept locked in her office and added that the school would be closed for two days at the beginning of the following week. The business manager then asked how she should deliver Mothers employment file to Fathers attorney.
T7 Fathers attorney informed the business manager that the documents could be scanned and faxed or emailed directly to her. Fathers attorney also indicated to the business manager that by transmitting the documents by fax or email in advance of the hearing, there was a good chance that the business manager would not have to testify or that the business manager could testify by phone to verify the documents, so long as Mothers attorney agreed. The schools business manager immediately seanned Mothers employment file in its entirety and emailed it to Fathers attorney. Less than an hour after issuing the corrected subpoena duces tecum, Fathers attorney was in possession of Mothers entire employment file.
T8 That same evening, Fathers attorney forwarded the documents to Mothers attorney by email and requested that Mother waive the need for the business managers appearance at the hearing. Fathers attorney also copied Father on the email, thereby providing Father with an electronic copy of Mothers entire employment file. The email from Fathers attorney to Mothers attorney stated in its entirety:
We have received Ms. Wiggins [sic] entire employment file. The email providing it and file [sic] are both attached. We do have a witness subpoenaed to authenticate the documents, explain how the records are kept, and verify that this is the entire file. However, because she has a job to do, she would appreciate having her appearance waived. We are hoping that you will agree to the authenticity of these documents and their admissibility without her testimony. Please advise whether you will stipulate to the admission of these documents. If not, please advise as to whether you will object to the witness testifying by phone. Thank you.
(Emphasis added.)
19 Because the return of service had not yet been received by Fathers attorney from the process server, Fathers attorney had not yet provided Mother with formal notice of the subpoena. Nor had Fathers attorney provided Mother with any notice of the subpoena. As such, Mother and Mothers attorney had no knowledge of the subpoena prior to Fathers attorneys email.
€10 In response, Mothers attorney protested Fathers and Fathers attorneys possession of Mothers employment file; claimed that it contained confidential and secure financial information and that it was improperly obtained by Fathers attorney; and demanded that Fathers attorney recover and return or destroy all physical and electronic copies of the documents, including all copies possessed by Father as a result of Fathers attorney copying him on the email. Fathers attorney refused, maintaining that the employment file had been acquired via a valid subpoena duces tecum.
T11 The hearing concerning parenting time and child support was continued, and Mother moved for a protective order and sanctions against Fathers attorney concerning the subpoenaed documents. The district court denied Mothers motion without explanation, and Mothers petition for our review followed.
II. Original Jurisdiction and Standard of Review
112 We first address whether an original proceeding is the proper method to review the trial court order denying Mothers motion for a protective order and sanctions. Exercise of our original jurisdiction under CAR. 21 is within our sole discretion. Fognani v. Young, 115 P.3d 1268, 1271 (Colo.2005). Even though a trial courts ruling on a discovery matter is interlocutory in character and is generally not reviewable in a CAR. 21 original proceeding, a discovery ruling is not exempt from extraordinary relief if it appears that the order may cause unwarranted damage to a litigant that cannot be cured on appeal. Cardenas v. Jerath, 180 P.3d 415, 420 (Colo.2008) (quoting Direct Sales Tire Co. v. Dist. Ct., 686 P.2d 1316, 1318 (Colo.1984)). We have previously exercised our original jurisdiction to review discovery rulings concerning documents that are alleged to be confidential, privileged, or otherwise protected. In re Dist. Ct., 256 P.3d 687, 690 (Colo.2011) (concerning compensation information); Cardenas, 180 P.3d at 420 (concerning medical records); Stone v. State Farm Mut. Auto. Ins. Co., 185 P.3d 150, 155 (Colo.2008) (concerning tax returns). In addition, [wle generally elect to hear CAR. 21 cases that raise issues of first impression and that are of significant public importance, Stamp v. Vail Corp., 172 P.3d 437, 440 (Colo.2007), and we have previously exercised our original jurisdiction to review questions of rule interpretation, Fognanmi, 115 P.3d at 1271 (interpreting Colo. RPC 3.7).
113 Following these legal standards, we conclude that exercise of our original jurisdiction is appropriate in this case. First, Mother seeks to protect her employment file from discovery, which she alleges contains personal, privileged, and confidential information such as bank account numbers and bank routing information, employment application information, her personal résumé and teacher lesson plans, educational transcripts and certifications, a performance appraisal, and her employment contract. Given the sensitive nature of this information, the trial courts summary denial of Mothers motion for a protective order may result in unwarranted and irreparable damage to Mother because it allows Father to maintain possession of Mothers entire employment file and permits Fathers unrestricted use of the information it contains.
T14 Second, this court has never before considered when and where Rule 45 requires the production of subpoenaed documents to oceur. A clear directive in this regard is essential to maintain fairness in the judicial process and to avoid abuses of the subpoena power for tactical advantage. The amicus curiae American Academy of Matrimonial Lawyers emphasize that this is particularly true in the context of family law cases where the breadth of potential inquiry into matters ranging from mental and physical health to income and assets invites discovery abuse. See, e.g., In re Marriage of Ensminger, 209 P.3d 1163, 1166-67 (Colo.App.2008) (upholding an award of attorney fees against an attorney who was found to have acted in bad faith and to have abused the judicial process in issuing a nonparty subpoena).
¶15 We review matters under C.A.R. 21 for abuse of discretion. E.g., Ortega v. Colo. Permanente Group, P.C., 265 P.3d 444, 447 (Colo.2011); Cardenas, 180 P.3d at 420.
III. Mootness
¶ 16 Next, we must consider Fathers argument that this issue is moot. An issue is moot if a judgment which, when rendered, cannot have any effect upon an existing controversy. Reserve Life Ins. Co. v. Frankfather, 128 Colo. 77, 79, 225 P.2d 1035, 1036 (1950). In addition, where subsequent events cause an issue to become moot, we will decline to entertain the merits of an appeal. See, e.g., Trinidad Sch. Dist. No. 1 v. Lopez, 963 P.2d 1095, 1102 (Colo.1998); Humphrey v. Sw. Dev. Co., 784 P.2d 637, 639-40 (Colo.1987).
117 Father contends that the issue raised in this appeal is moot because Mothers employment file was sought from Mothers former employer in connection with Mothers motion to modify child support, a motion which Mother has since withdrawn. We are not persuaded. We acknowledge that Fathers attorney obtained Mothers employment file in connection with Mothers motion to modify child support, but there is no rule or court order that confines Fathers use of that discovered information to that particular motion. It is undisputed that the post-dissolution decree litigation between the parties is ongoing and exceptionally contentious. It is also undisputed that Fathers attorney and Father are still in possession of Mothers employment file, which Mother alleges contains personal, privileged, and confidential information. If Father is permitted to retain possession of Mothers employment file, then he will be free to use the information as he would use any other discovery information. For example, he may attempt to introduce the information as evidence in another proceeding, or he may seek to use the information as a means to discover other evidence. Therefore, Fathers right to retain possession of Mothers employment file is still an existing controversy. The central issue raised by Mother is whether Fathers attorney improperly obtained subpoenaed documents from Mothers former employer. It would be antithetical to the rules governing civil discovery to allow a party to retain possession of discovery information that has been obtained improperly. See, e.g., C.R.C.P. 37(c)(1) (prohibiting a party who fails to disclose information from using such information at trial). Therefore, the fact that Mother has withdrawn her motion to modify child support does not render the issue moot.
¶ 18 Alternatively, Father argues that this issue is moot because although a subpoena was served on the schools office manager, no subpoena was ever served on the schools business manager, who produced Mothers employment file after informing Fathers attorney that the schools office manager did not have authority to access or verify the schools employment files. Father maintains that because no subpoena was ever served on the business manager, the business managers production of Mothers employment file was wholly voluntary. Again, we are not persuaded. There is no doubt that the subpoena served on the schools office manager was intended to secure documents possessed by the school and not documents individually possessed by the office manager herself. Nor is there any confusion that when the schools business manager called Fathers attorney to explain that the office manager had no access to Mothers employment file and to ask how she should deliver the employment file to Fathers attorney, the business manager believed that she was fulfilling the schools obligation to comply with the subpoena.
¶ 19 Had Fathers attorney believed that the business manager was providing the documents voluntarily and not under subpoena, there would have been no reason for Fathers attorney to explain that the business manager would still have to appear in court the following week pursuant to the subpoenas. Furthermore, had Fathers attorney believed that the business manager was providing the documents voluntarily, she would not have stated in her emails to Mothers attorney that there was a witness subpoenaed to authenticate the documents, explain how the records are kept, and verify that this is the entire file or that Mothers employment file had been obtained via a valid subpoena duces tecum.
{20 Thus, it is clear that the purpose of the subpoena was to obtain Mothers employment file from the school and not from any particular individual working at the school. The conduct of Fathers attorney cannot escape review on the technicality that the subpoena was served on the schools office manager but responded to by the schools business manager. We therefore reject Fathers alternative mootness argument and proceed with our analysis.
IV. Analysis
{21 In order to determine whether Fathers attorney violated Rule 45, we first examine the language of Rule 45. We then apply the rule to the facts of this case and consider the issue of sanctions.
A. Rule 45 Examined
{22 We begin with Rule 45. Rule 45 sets forth the formal process by which an attorney may invoke the subpoena power to require the attendance of a witness at a deposition, hearing, or trial, and to acquire documents from that witness:
Subpoenas may be issued under Rule 45 only to compel attendance of witnesses, with or without documentary evidence, at a deposition, hearing or trial Every subpoena ... shall command each person to whom it is directed to attend and give testimony at a time and place therein specified.
A subpoena may also command the person to whom it is directed to produce the books, papers, documents, or tangible things designated therein. ..."
C.R.C.P. 45(a)-(b).
¶ 23 Whether Fathers attorney violated Rule 45 when she accepted delivery of subpoenaed documents in advance of the time and place specified in the subpoena depends on whether the rule governs where and when the production of subpoenaed documents must occur. Mother contends that the rule requires production only at the designated deposition, hearing, or trial. In response, Father argues that no violation of Rule 45 occurred because the rule is silent as to whether a subpoenaed witness may produce subpoenaed documents in advance of the time and place specified in the subpoena.
¶ 24 The standard principles of statutory construction apply to our interpretation of court rules, including the rules of civil procedure. Leaffer v. Zarlengo, 44 P.3d 1072, 1078 (Colo.2002). Accordingly, we first aim to interpret a rules language consistent with its commonly understood and accepted meeting. Id. If the rule is unambiguous, then we apply the rule as written. See People v. Angel, 2012 CO 34 ¶ 17, 277 P.3d 231.
{25 We have previously explained that Rule 45 does not permit an attorney to subpoena documents by themselves; rather, a subpoena for the production of documents may be sought only in connection with a subpoena for a witnesss attendance at a deposition, hearing, or trial. Colo. Mills, LLC v. SunOpta Grains & Foods Inc., 2012 CO 4, ¶ 20 n. 8, 269 P.3d 731, 735 n. 8; In re Atty. E., 78 P.3d 300, 305 (Colo.2003); Feigin v. Colo. Nat. Bank, N.A., 897 P.2d 814, 818 (Colo.1995).
¶ 26 The authority of an attorney to subpoena documents under Rule 45 comes from the prepositional phrase with or without documentary evidence, which is couched within the rules principal power to require a witness to attend and testify at a deposition, hearing, or trial. C.R.C.P. 45(a). In addition, the rules use of the adverb only constrains the purpose and operation of the subpoena power, restricting its application only to compel attendance of witnesses and only at a deposition, hearing or trial. Id. Taken together, these two linguistic devices restrict the time and place for the production of subpoenaed documents to the deposition, hearing, or trial where the witness must attend and testify. Id.; CBA Ethics Comm., Rev. Formal Op. 86 (Rev. 1998) ([C.R.C.P.] 45 only authorizes the production of documents pursuant to a subpoena duces tecum at a deposition, hearing or trial. ). Thus, the plain language of Rule 45 unambiguously prohibits an attorney from accepting subpoenaed documents from a subpoenaed witness in advance of the specified deposition, hearing, or trial.
127 By requiring that subpoenaed documents be produced only at the specified deposition, hearing, or trial, Rule 45 balances the right to obtain information and evidence with the right to shield information from disclosure by ensuring sufficient opportunity for the subpoenaed witness, other parties to the case, or any other person claiming an interest in the subpoenaed documents to object to the subpoenas. See C.R.C.P. 45(b)(1) (permitting motions to quash or modify a subpoena at or before the time specified in the subpoena for compliance therewith); C.R.C.P. 45(d)(1) (permitting motions for protective order).
128 The opportunity to object to a subpoena is a vital protection of Rule 45 that is safeguarded not only by the rules requirement that subpoenaed documents be produced only at the specified deposition, hearing, or trial, but also by the rules requirement that all other parties to the case receive notice of the subpoena promptly after it is served on the subpoenaed witness. See C.R.C.P. 45(c) (Service on other parties shall be made promptly after the service of the subpoena upon the person named therein.). For these reasons, production of subpoenaed documents in advance of the specified event would obstruct the right of a party, the subpoenaed witness, or other interested persons and would frustrate the purpose of the rule to fairly marshal the evidence of a case. See Colo. RPC 8.4 emt. 1 (The procedure of the adversary system contemplates that the evi-denee in a case is to be marshaled competitively by the contending parties.). Fair competition for evidence is secured by the rules of civil procedure, as well as by the ethical obligations imposed on lawyers by Colorados Rules of Professional Conduct. See CBA Ethics Comm., Rev. Formal Op. 86 (Knowingly violating the requirement of [C.R.C.P.] 45(a) that documents responsive to a subpoena be produced only at a deposition, hearing, or trial ... may deprive a party or witness of vital protections, and is unethical.); see also Colo. RPC 3.4 (concerning fairness to opposing party and opposing counsel); Colo. RPC 4.3 (concerning dealings with unrepresented parties); Colo. RPC 4.4 (concerning respect for rights of third persons).
¶ 29 Father submits that it is common practice for subpoenaed documents to be produced in advance of the time and place specified in the subpoena. We do not doubt the validity of this assertion nor do we rebuke the practice so long as all of the parties and the subpoenaed witness consent to the alternate arrangement, or if the trial court so orders. Accordingly, if an attorney desires to receive subpoenaed documents from a sub-poenged witness in advance of the time and place specified in the subpoena, or if the subpoenaed witness offers to produce the documents ahead of time, then the attorney must confer with and obtain consent from all other parties to the case as well as the subpoenaed witness. If the other parties or the subpoenaed witness do not consent, then production must wait until the time and place of the event specified in the subpoena. Obtaining consent for the advance production of subpoensed documents not only satisfies Rule 45s procedural safeguards but also affords pragmatic accommodation to the realities of litigation practice.
C. Rule 45 Applied
¶ 30 In accordance with Rule 45, the subpoena issued by Fathers attorney ordered Mothers former employer to attend and give testimony at the then-scheduled October 13 hearing and also to produce then and there the documents listed in the attached Exhibit A (Emphasis added.) Almost immediately after receiving the subpoena, the schools business manager called Fathers attorney to inform her that the schools office manager, who was named in the subpoena, was not authorized to access or verify the schools personnel files. The business manager further explained that she keeps the schools personnel files locked in her office and that the school would be closed for two days the following week. The business manager then asked Fathers attorney how she should deliver Mothers employment file in response to the subpoena. Instead of explaining that the subpoena did not require production of the documents until the hearing date the following week or that the school had the right to withhold any privileged documents or that it might be possible for the business manager to provide the documents in advance of the hearing but that permission from Mother would be required, Fathers attorney directed the business manager to sean and fax or email the documents directly to her, which the business manager did immediately. These unilateral arrangements violated Rule 45 because they prevented Mother from having an opportunity to object to the subpoena before her entire employment file was disclosed.
{31 Compounding the issue is the fact that, at the time that Fathers attorney made arrangements with the schools business manager for the production of Mothers employment file, notice of the subpoena had not even been served on Mother. Father contends that his attorney did not violate the notice requirements of Rule 45 because the rule requires notice promptly after service of the subpoena has been made on the witness and that his attorney did not receive the return of service from the process server until the Monday after service was made, at which time Fathers attorney electronically entered the return of service thereby providing formal notice of the subpoena to Mother. That may be so, but the fact that Fathers attorney made arrangements for the advance production of the subpoenaed documents with clear knowledge that Mother had not yet received notice of the subpoena further highlights the impropriety of her actions. By directing the schools business manager to produce the subpoenaed documents at a time when Mother had no knowledge of the subpoena, Fathers attorney did not merely obstruct Mothers right to object to the sub-poenga, she effectively extinguished that right altogether. As such, we hold that the manner by which Fathers attorney obtained Mothers employment file and any other doe-uments from the school in response to the subpoena violated Rule 45.
132 Mother makes the additional argument that Fathers attorney obtained her employment file in violation of Rule 45 because employment files are presumed to be protected from discovery. Because our holding that Fathers attorney violated Rule 45 does not depend on whether the documents obtained are privileged, confidential, or otherwise protected, we decline to address this additional argument.
D. Sanctions
133 Last, we address Mothers argument that the violation of Rule 45 by Fathers attorney rises to the level of an abuse of discovery and warrants sanctions against Fathers attorney pursuant to section 13-17-102(4), C.R.S. (2011), because Mothers employment file contained confidential, privileged, or otherwise protected information. Pursuant to section 13-17-102(4), a court shall assess attorney fees if it finds that an attorney unnecessarily expanded the proceeding by abusing the rules of discovery. To determine whether to assess attorney fees, the court is required to set forth the reasons for its award and to consider the factors, among others, enumerated in section 13-17-103, C.R.S. (2011). Although we hold that Fathers attorney violated Rule 45 when she arranged for the advance production of Mothers employment file from Mothers former employer, we leave it to the trial court to determine whether sanctions are appropriate in this case.
V. Conclusion
84 For the foregoing reasons, we make the rule absolute, reverse the trial courts order, remand the case to the trial court, and direct the trial court to ensure that Father and Fathers attorney identify and recover, and then return or destroy all physical and electronic documents produced by Mothers former employer pursuant to the subpoena issued by Fathers attorney, including Mothers entire employment file. On remand, we also direct the trial court to determine, in accordance with sections 13-17-102(4) and 13-17-1083, whether attorney fees should be levied against Fathers attorney for her violation of Rule 45.
. It was not until approximately noon on the following Monday-Columbus Day-that Fathers attorney electronically transmitted the return of service to Mothers attorney, which provided formal notice of the subpoena to Mother.
. There are, however, two exceptions to the mootness doctrine, and we may review a moot issue if (1) the issue is capable of repetition, yet evades review; or (2) the matter involves a question of great public importance. In re Marriage of Balanson, 25 P.3d 28, 38 n. 3 (Colo.2001).
. Father also contends: (1) that Mothers reference to the employment file in certain sworn discovery responses constitutes a waiver of any claim of confidentiality, which estops Mother from now alleging that the documents are confidential; and (2) that the timing and purpose of Mothers appeal was merely a tactic to prejudice Father at the trial courts hearing on Fathers motion to modify parenting time. Father claims that the appellate filing caused his attorney to be loathe to use the information contained in the employment file to impeach Mothers testimony at the parenting time hearing, resulting in the trial courts finding that Mother was wholly credible and Father was not.
We reject both of these contentions. First, because our holding that Fathers attorney violated Rule 45 does not turn on whether the documents obtained by Fathers attorney were confidential in nature, whether judicial estoppel applies based on Mothers prior statements or representations is irrelevant here. Second, whether Fathers attorney chose to alter her trial strategy for the parenting time hearing as a result of Mothers appellate filing is also irrelevant to our inquiry. Mothers appeal was properly filed pursuant to C.A.R. 21 and relates solely to the trial courts order denying her motion for a protective order and sanctions.
. Assuming arguendo that Fathers mootness argument had merit, the exceptions to the mootness doctrine would apply in this case to permit our review of this issue for the same reasons set forth in section II, supra, concerning the exercise of our original jurisdiction over this case.
. A subpoena may be issued without court order by an attorney of record or by the clerk of court in which the action is pending. C.R.C.P. 45(e).
. Colorados Rule 45 is different from its federal counterpart, which authorizes the issuance of a subpoena duces tecum independently from the issuance of a subpoena to attend and testify: A command to produce documents, electronically stored information, or tangible things or to permit the inspection of premises may be included in a subpoena commanding attendance at a deposition, hearing, or trial, or may be set out in a separate subpoena. FRCP. 45(a)(1)(C) (emphasis added); see also 12 Debra Knapp & Kelly Ryan, Colo. Civil Proc. Forms & Commentary § 45.7 (2d ed. 2012).
. This notice to opposing parties is especially important in light of the fact that a subpoenaed witness will often be unrepresented and less sophisticated as to his or her rights to object to the subpoena. See CBA Ethics Comm., Rev. Formal Op. 86 (During any communication with a non-party witness, a lawyer should keep in mind that the imbalance in knowledge and skill between a lawyer and lay witness may cause even well intentioned acts of the lawyer to have a coercive impact on the witness and induce the witness to disclose privileged or confidential information.). On its face, a subpoena duces tecum looks like an order from the court. A lay party might, understandably, fear that any failure to comply with the subpoena will be unlawful per se, which in some cases will not be true. The lay party will thus be eager to comply fully and quickly with the subpoenas requirements.
. Such conduct would be tantamount to any other surreptitious and unilateral act such as cancel-ling a deposition subpoena without the agreement of opposing counsel. See CBA Ethics Comm., Abstract 98/99-02 (1999).
. We do not consider or address whether Fathers attorney violated the Rules of Professional Conduct when she violated Rule 45. See Mercantile Adjustment Bureau, LLC. v. Flood, 2012 CO 38 ¶ 15, 278 P.3d 348 ([Plossible ethical violations arising during litigation are better addressed by the comprehensive disciplinary machinery of the bar.).
. The Ethics Committee of the Colorado Bar Association has instructed that it is ethical to send a cover letter to a subpoenaed nonparty witness indicating that the witness may produce the subpoenaed documents in advance of the time and place specified in the subpoena, provided there are not claims of privilege with respect to the requested documents. CBA Ethics Comm., Abstract 98/99-02. We interpret this instruction as consistent with the holding of this opinion that advance production of subpoenaed documents is prohibited by Rule 45 unless all parties and the subpoenaed witness consent.
. For the reasons stated in note 7, supra, attorneys must use extra caution in their communications when seeking consent from a subpoenaed witness for the advance production of subpoenaed documents, including in a subpoena cover letter. The Ethics Committee of the Colorado Bar Association advises lawyers that their letter should: (1) identify the lawyer clearly; (2) state the reason for the communication; (3) inform the subpoenaed nonparty witness that the subpoena does not require the witness to disclose information to the lawyer other than at the specified deposition, hearing, or trial; (4) inform the witness that he or she has the right to withhold any privileged documents; and (5) tell the witness to consult his or Ker attorney with questions regarding what constitutes privileged documents or information. CBA Ethics Comm., Abstract 98/99-02; see also CBA Ethics Comm., Rev. Formal Op. 86.
. In pertinent part, section 13-17-102(4) provides: The court shall assess attorney fees if, upon motion of any party or the court itself, ... it finds that an attorney or party unnecessarily expanded the proceeding by other improper conduct, including but not limited to, abuses of discovery procedures available under the Colorado rules of civil procedure. ...
. We have previously commented that [a] subpoena duces tecum issued pursuant to CRCP. 45(b) is designed to produce evidence at trial but is not intended as a discovery device. Watson v. Regl Transp. Dist., 762 P.2d 133, 141 n. 12 (Colo.1988). However, when a Rule 45 subpoena is used as a discovery device, the rules of discovery apply. See Keplinger v. Va. Elec. & Power Co., 208 W.Va. 11, 537 S.E.2d 632, 641-42 (2000).