The Court holds that, although 3 V.I.C. § 530a(d)-notwithstanding its reference to the appellate jurisdiction of the "District Court"-authorizes litigants to appeal all decisions of the Superior Court entered pursuant to petitions for writ of review challenging PERB decisions, this statute is inapplicable to the instant case because section 530a(d) was not adopted until 2002 and the underlying writ of review action was brought in 2001 pursuant to the general writ of review statute. However, the Court holds that it possesses jurisdiction over the appeal pursuant to the collateral order doctrine. The Court further holds that the Superior Court possessed jurisdiction over the petition for writ of review even though it was untimely filed pursuant to Superior Court Rule 15(a) because, to the extent Rule 15(a) is a claims-processing rule, the Government and PERB's failure to challenge the timeliness of the petition resulted in waiver of that rule's protections. Furthermore, to the extent Rule 15(a) is jurisdictional, the general writ of review statute, by incorporating all rules of the Superior Court rather than only Rule 15(a), also incorporated Superior Court Rule 10, which allows the Superior Court to grant extensions of time. With respect to the merits, the Court holds that the Superior Court correctly applied a de novo standard of review to PERB's legal conclusions because the pertinent statutes did not contain any ambiguous language, and further holds that the Superior Court correctly held that exempt employees who elected into the classified service pursuant to the former 3 V.I.C. § 498 possessed all the rights and privileges of a classified employee, including the right to appeal a termination to PERB. Finally, the Court holds that the Government and PERB waived any challenge to the Superior Court's consideration of evidence that was allegedly not part of the administrative record by failing to object to admission of that evidence at any point in the Superior Court proceedings.