Gerald G. Neill, Jr., appeals the Superi- or Court’s dismissal of his petition for review of a decision by the Public Employee Relations Board (the “PERB”). We conclude that the trial court erred in dismissing the petition on account of Neill’s failure to name the PERB as a respondent and serve the petition on it before the thirty-day filing deadline. We reverse and remand for the trial court to proceed with its consideration of Neill’s petition for review.

I.

Neill, a former Metropolitan Police Officer, served as Chairman of the intervenor police union (the “FOP”) from 2000 to 2004. During Neill’s tenure, the FOP terminated its contract with its general counsel, Ted Williams. In response, Williams sued both Neill and the new general counsel, alleging breach of contract, tortious interference with contract, and intentional infliction of emotional distress. After a series of procedural disputes of minimal importance here,1 the Superior Court granted Neill’s motion for summary judgment in 2009.

On March 15, 2010, Neill filed a “standards of conduct” complaint against the FOP with the PERB. Public sector unions in the District are statutorily required to certify their compliance with certain standards of conduct, including one obligating them to maintain “provisions defining and securing the right of individual members ... to fair and equal treatment under the governing rules of the organization....”2 The PERB has jurisdiction to hear complaints alleging that a recognized union failed to comply with the specified conduct standards.3 Neill’s complaint alleged such a violation in the FOP’s refusal to pay for his defense of Williams’s lawsuit despite a provision in its bylaws guaranteeing legal representation to union members for the defense of civil actions arising out of the performance of their duties.

Standards of conduct complaints must be filed with the PERB within 120 days “from the date the alleged violation(s) occurred.” 4 This deadline has been held to be “jurisdictional and mandatory.”5 On *233February 4, 2012, the PERB, reading Neill’s pleading to allege that the union denied his request for legal representation in 2008, dismissed his complaint as untimely.6 On March 1, 2012, Neill petitioned for review of the PERB’s decision in Superior Court.

Petitions for review of PERB decisions in Superior Court must be filed within thirty days of their issuance.7 Neill filed his petition before the expiration of this deadline. However, his petition did not name the PERB as the respondent (though it identified the PERB decision Neill sought to have reviewed), and he did not serve the petition on the PERB. Instead, Neill named the FOP as the respondent, and he served the FOP and the Attorney General for the District of Columbia.

On June 21, 2012, well after the thirty-day window for filing a petition had closed, Neill’s attorney contacted the PERB to ask why it had not filed the agency record with the Superior Court, as it normally would do.8 The PERB’s general counsel informed Neill’s attorney that the PERB, as an independent agency, was not represented by the D.C. Attorney General in appeals of PERB decisions. Because Neill had not served the PERB with his petition, its general counsel explained, it was not a party to the appeal and so had no obligation to file the record. Moreover, the PERB’s counsel asserted, Neill’s failure to serve the PERB within the thirty-day filing period meant that its decision had become final. That same day, Neill served the PERB with his petition. He later filed an amended petition for review naming the PERB as the respondent, after being prompted to do so at a June 29 initial scheduling hearing in Superior Court.

Based on Neill’s failure to name the PERB as the respondent in his initial petition for review and failure to serve that *234petition on the PERB before the expiration of the thirty-day filing deadline, the PERB moved to dismiss for lack of subject matter jurisdiction. The Superior Court granted the motion, dismissed Neill’s petition with prejudice, and denied his motion for reconsideration. Neill noticed this timely appeal.

II.

We agree that Neill was required by the Superior Court’s Rules to name the PERB as the respondent in his petition for review, and to serve his petition on the PERB within the thirty-day filing deadline. We conclude, however, that Neill’s non-compliance with those requirements did not deprive the Superior Court of jurisdiction over his petition or otherwise justify its dismissal. Accordingly, we reverse; on remand the court will have discretion to decide whether to impose lesser sanctions for Neill’s missteps.

A.

The Comprehensive Merit Personnel Act (“CMPA”)9 provides for appeals from decisions of the PERB (the body charged with adjudicating public sector labor disputes and other public employee matters) and the Office of Employee Appeals (the entity primarily responsible for reviewing certain serious adverse employment actions) to be taken to the Superior Court.10 To implement that requirement and govern such appeals, the Superior Court adopted Agency Review Rule l.11 Among other things, Rule 1 specifies the time and manner for filing petitions for review in CMPA cases, and to furnish additional guidance, is accompanied by a form petition for review for litigants to use as a model. The PERB contends, and the Superior Court agreed, that Neill’s initial petition did not satisfy the requirements of Rule 1 with respect to naming the agency as respondent and serving it with the petition, and that those requirements are jurisdictional. Neill disputes their interpretation of Rule 1 and their jurisdictional claims.

The interpretation of a rule of procedure is a question of law as to which our review is de novo.12 We do not agree that the Superior Court misunderstood Rule l’s requirements. To begin with, although the text of Rule 1 and the accompanying form petition do not say so explicitly, we heretofore have held that the Rule requires a petitioner to name the PERB (or the Office of Employee Appeals, as the case may be) as the respondent in the caption of his petition for review.13 A petition that fails to name the PERB in the caption, and that instead names the opposing party in the agency proceeding as the respondent, is noncompliant even if the petition elsewhere correctly identifies the PERB as the agency that issued the order from which relief is sought (as Neill’s petition did in this case).14

Disputing this interpretation of Rule 1, Neill argues that he properly named the FOP as the respondent because the PERB lacks constitutional standing to *235defend its decision.15 That is incorrect. We have explained that an agency presumptively “must carry the burden of defending its action in any challenge to it” because the “matters raised in” such a challenge “go directly to the [agency’s] authority and to the validity of its decision, which the [agency] has a substantial interest in defending.”16 Neill’s argument that this presumption does not apply to the PERB is contradicted by our decision in IBPO, which noted that the PERB was “the only entity that could afford the relief sought.”17

In asserting that the PERB nonetheless lacks standing, Neill relies on cases from other jurisdictions holding that particular agencies were without statutory authorization to litigate in court.18 But the CMPA expressly empowers the PERB to litigate the validity of its decisions.19 Neill rejoins that the PERB’s interest in defending its decisions on the merits does not create an interest (sufficient for standing) in enforcing its “procedural right,”20 i.e., the statutory time limit for seeking review. That contention too is incorrect, for the time bar plays an obvious role in ensuring the enforceability of the PERB’s decisions.21 We reject Neill’s standing argument and hold that his initial petition for review contravened Agency Review Rule 1 by failing to name the PERB as the respondent.22

*236Whether Rule 1 also required Neill to serve the PERB is a question this court previously has not had occasion to resolve. On its face, the Rule can be read to suggest otherwise, because subsection (a) provides only that a petition for review must “show service ... upon all other parties to the agency proceeding and the Office of the Corporation Counsel of the District of Columbia.”23 No lawyer would think of the PERB as a party to its own proceeding, and the requirement of service on the Attorney General24 might be taken to imply that service on the PERB is unnecessary. Neill argues that service on the Attorney General was indeed sufficient to serve the PERB.

Nevertheless, the better reading of Rule 1 is that it does require petitions for review to show service on the agency that conducted the proceeding below. Subsection (e) of the Rule states that the adjudicating agency must file the record with the Superior Court “[wjithin sixty (60) days from the date of service of petition upon the agency and the office of the Corporation Counsel,”25 and the comment to the Rule explicitly states that the “petition must be served on the agency involved with a copy to the attorney in the office of the Corporation Counsel handling the case.”26 Reading the Rule in its entirety together with its explanatory comment27 thus makes clear that the agency must be served as well as the Attorney General, and the Rule makes only one party — the petitioner — responsible for service.28 There is no solid textual basis for reading the Rule to require a different party — for example, the Attorney General or the Clerk of the Superior Court — to serve the agency.29 And it would be anomalous to place the burden of serving the PERB on the Attorney General, as Neill proposes, given that the PERB is an independent agency with its own general counsel, and that the Attorney General often represents one side (the District government) in disputes adjudicated by the PERB — i.e., disputes between the District and its public *237sector unions.30

Having said this, it must be acknowledged that the text of Rule 1 is misleading. We think the Superior Court would do well to amend it to state unambiguously that petitions for review of agency decisions under the CMPA must (1) name the agency that issued the decision being appealed as the respondent in the caption and (2) show service by the petitioner on that agency, all other parties to the agency proceeding, and the Attorney General for the District of Columbia.31 The form petition accompanying the Rule should reflect these requirements. Additionally, we suggest that the PERB consider adopting the practice of other District agencies of attaching to its decisions instructions detailing how, where, and when an aggrieved party may seek review.

B.

We now turn to the question of whether Neill’s initial failures to name and serve the PERB deprived the Superior Court of subject matter jurisdiction to review the PERB’s decision even though Neill filed his petition within the thirty-day period specified by D.C.Code § l-617.13(c) and Rule 1 and otherwise complied with their requirements. The issue of subject matter jurisdiction is a question of law as to which our review is de novo.32

We read this court’s decision in IBPO to hold that Neill’s failure to name the PERB as respondent did not divest the Superior Court of jurisdiction. In that case, after concluding that the petitioner violated Rule 1 by not naming the PERB as respondent, the court explained that “this is not the kind of rules violation that calls for per se dismissal.”33 The court contrasted the captioning failure with “mandatory and jurisdictional” filing requirements, such as time limits for filing.34 Had the court thought jurisdiction to be in doubt, it would have said so.35

More recent cases lead us to the same conclusion. The Supreme Court and *238this court have striven to differentiate jurisdictional rules that limit the court’s authority to hear a case from non-jurisdictional “claim-processing” rules that “seek to promote the orderly process of litigation by requiring that the parties take certain procedural steps at certain times.”36 Jurisdictional limitations, when not constitutionally mandated, are an exercise of legislative power and so must be grounded in statutes or other legislative acts; absent a proper delegation of that power to the judiciary, procedural requirements imposed only by court rule are not jurisdictional in nature — they are claim-processing rules that (unlike the requirements of subject-matter jurisdiction) may be relaxed or waived.37

Indeed, the Superior Court Rules of Civil Procedure state explicitly that they “shall not be construed to extend or limit the jurisdiction of this Court.”38 It is true, as we have indicated, that a jurisdictional provision in a statute may (explicitly or implicitly) delegate or leave to the court the responsibility to specify or define the precise jurisdictional condition in a rule, thereby rendering the rule jurisdictional to that extent. For example, the District of Columbia Administrative Procedure Act provides that petitions for review in this court “shall be filed ... within such time as [this court] may by rule prescribe ....”39 We have held that our implementing rule, which provides a thirty day period for a party to seek review, is jurisdictional.40 Similarly, D.C.Code § 11-721 (2012 Repl.) provides that this court has jurisdiction to hear appeals by aggrieved parties from orders or judgments of the Superior Court. How, then, does an aggrieved party “appeal”? The statute does not spell that out, but our implementing rule specifies it is done by filing a notice of appeal that identifies the appellants) and the judgment or order being appealed.41 We have held these definitional requirements to be jurisdictional.42 The Supreme Court likewise has held that “both a notice [of appeal] and its contents are jurisdictional prerequisites.”43 But *239this certainly does not mean that the caption or form of an otherwise compliant notice has jurisdictional significance.44 Nor do the foregoing cases mean that the various other procedural requirements imposed by rule for perfecting a petition for review of agency action or an appeal from the Superior Court are jurisdictional.45

The relevant statute in this case, D.C.Code § l-617.13(c), does not specify that petitions for review of PERB decisions must name the deciding agency as respondent in the caption of the petition; it simply states that “[a]ny person aggrieved by a final order of the Board ... may obtain review of such order by filing a request within 80 days after the final order has been issued.” There is no doubt that Neill filed such a request, or that in it he identified himself, the PERB, and the final order he sought to have reviewed. The formal pleading requirement with which Neill failed to comply, that the PERB be identified as the respondent, derives only from Rule 1. It may be an important claim-processing requirement, but it is not part of the essential definition of a “request” for review. No statute delegates to the Superior Court the authority to impose such a technical pleading requirement as a jurisdictional prerequisite to the review of PERB decisions. We therefore are comfortable reaffirming the implicit holding of IBPO that, while a petitioner’s failure to name the agency as respondent in a Rule 1 petition for review may have other consequences, it does not divest the Superior Court of jurisdiction.

Turning to Neill’s failure to effect timely service on the PERB, the CMPA does not impose any particular service requirement as a condition of invoking the jurisdiction of the Superior Court. As we have emphasized, D.C.Code § l-617.13(c) provides that “filing” a timely request is all a person aggrieved by a final order of the PERB need do to obtain judicial review. “Filing” is a term of limited meaning; it does not encompass the concept of service.46 Service of process goes to the court’s power over the party to be served, *240not the court’s ability to consider the subject matter of the case, i.e., its subject-matter jurisdiction.47 Our cases reflect that distinction. For example, in the analogous context of petitions for review filed in this court, we have rejected the argument that a petitioner’s failure to timely serve intervenors affects the court’s subject matter jurisdiction.48 And insufficiency of service may be waived,49 while subject matter jurisdiction may not.50 We readily conclude that the service requirements of Agency Review Rule 1 are not jurisdictional in character, and that Neill’s failure to serve the PERB within the thirty-day filing period therefore did not divest the Superior Court of subject matter jurisdiction over his petition.

C.

Finally, we consider whether Neill’s non-compliance with Rule 1, although it did not deprive the court of subject matter jurisdiction, nevertheless justified dismissal (with or without prejudice).51 Superior Court Civil Procedure Rule 41(b) gives the trial court authority to dismiss any claim or action for failure of the plaintiff to comply with procedural rules, including, in principle, captioning and service irregularities.52 However, because Neill’s errors were not willful, the record does not show prejudice to the other parties, and the trial court did not consider alternative sanctions, we conclude that dismissal of the petition was unwarranted.

Some claim-processing rules, although not jurisdictional, are considered “inflexible,” meaning they are strictly enforced when the opposing party properly invokes *241them.53 IBPO made clear that the captioning rule is not in that category.54 As to the service requirement of Rule 1, analogous provisions in the Civil Rules allow for a case to proceed despite improper or untimely service if the court finds good cause why the case should not be dismissed — i.e., that the violation should be excused.55 We conclude similarly that imperfect service under Rule 1 does not require automatic dismissal.

Because neither the captioning nor the service requirement is “inflexible,” the trial court, in exercising its Rule 41(b) authority, has discretion to determine the penalty for noncompliance with them.56 Because of its severity, however, dismissal may be imposed as a sanction for the failure to comply with procedural requirements or other misconduct only in “extreme circumstances and only after the trial court has considered lesser sanctions.” 57 The court must consider “whether the conduct calling for sanctions was willful and whether the other party was prejudiced by it, and the sanction imposed should, wherever possible, be tailored to the offense.”58 “[A]t least as a general proposition, dismissal with prejudice is an appropriate sanction only upon clear evidence of deliberate delay or upon a showing of contumacious conduct by the plaintiff.” 59

Judged by those standards, it cannot be maintained that Neill’s initial failure to properly caption and serve his petition for review was sufficient justification for dismissing his petition. Neill’s errors plainly appear to have resulted from inadvertence or negligence at worst, not “contumacious conduct.”60 Once Neill’s attorney learned that he was required to serve the PERB, he did so promptly. Similarly, when advised to do so by the trial court, Neill without delay submitted an amended petition with a proper caption. And although Neill’s errors caused a somewhat lengthy delay, the PERB and the union *242suffered no evident prejudice as a result.61

Our conclusion that dismissal was too severe a sanction is confirmed by our cases. In IBPO, we held that failing to name the PERB as respondent did not require dismissal because the body of the petition correctly identified the PERB as the agency that issued the order from which relief was sought.62 The same is true here. In addition, the PERB “received actual notice of the suit, was properly served, filed responsive pleadings, and obtained the consent of all parties to intervene in the proceeding,” and thus “acted, for all practical purposes, as the respondent it truly [was].”63 Ultimately, that was true here as well.

The only meaningful difference between this case and IBPO is the timing of service on the agency. It is undeniable that Neill’s failure resulted in a significant delay. The PERB should have been served on March 1; it was not served until June 29. The agency record should have been filed by April 30; it was not filed until October 2. Nonetheless, according to the docket, nothing of significance occurred during that time other than the scheduling and re-scheduling of an initial conference. There is no indication, on this record at least, that the delay compromised the defense of the PERB’s decision or caused the FOP to incur costs by litigating in place of the agency. And unaccompanied by willful misconduct or prejudice, the delay of a few months was not so prolonged that it could be said to justify the sanction of dismissal by itself.64

This court’s decision in Francis v. Recycling Solutions, Inc.,65 on which the PERB relies, provides an apt contrast. In that case, we upheld the trial court’s dismissal of a lawsuit challenging the award of a recycling contract where the plaintiff (the losing bidder) incorrectly named as the defendant the winning bidder rather than the agency that made the award. The plaintiff had not served the agency and had fought against its entry in the litigation as a party, imposing court costs and attorney’s fees on the winning bidder forced to litigate the case in the agency’s stead.66 And in addition to naming the wrong defendant, the plaintiff, the director of a District of Columbia governmental agency, was herself an improper party, for she lacked the statutory authority to sue.67 None of those factors is present here.68

Neill’s mistakes were not willful and did not cause the kind of harm that justifies dismissal. Indeed, on this record, it does not appear that the PERB or the union *243suffered any prejudice at all. We recognize, however, that the trial court has never squarely considered the issue of prejudice. On remand, therefore, it remains open for the court to do so and, if it deems it appropriate, to fashion a remedy “tailored to the offense,” for example an award of costs.69

III.

For the foregoing reasons, we reverse the Superior Court’s dismissal of Neill’s petition for review and remand for further proceedings consistent with this opinion.

So ordered.