Pioneer Corp. v. Godfrey, 2019 SCC 42 (CanLII)
 This Court has recognized that limitation periods may be subject to a rule of discoverability, such that a cause of action will not accrue for the purposes of the running of a limitation period until “the material facts on which [the cause of action] is based have been discovered or ought to have been discovered by the plaintiff by the exercise of reasonable diligence” (Central Trust Co. v. Rafuse, 1986 CanLII 29 (SCC), (1986) 2 S.C.R. 147, at p. 224; Ryan, at paras. 2 and 22).
 This discoverability rule does not apply automatically to every limitation period. While a “rule”, it is not a universally applicable rule of limitations, but a rule of construction to aid in the interpretation of statutory limitation periods (Peixeiro v. Haberman, 1997 CanLII 325 (SCC), (1997) 3 S.C.R. 549, at para. 37]). It can therefore be displaced by clear legislative language (Ermineskin Indian Band and Nation v. Canada, 2006 FCA 415, (2007) 3 F.C.R. 245, at para. 333, aff’d 2009 SCC 9, (2009) 1 S.C.R. 222). In this regard, many provincial legislatures have chosen to enact statutory limitation periods that codify, limit or oust entirely discoverability’s application, particularly in connection with ultimate limitation periods (see e.g. Limitations Act, 2002, S.O. 2002, c. 24, Sch. B, ss. 4-5 and 15; Limitations Act, R.S.A. 2000, c. L-12, s. 3(1), Limitation Act, S.B.C. 2012, c. 13, ss. 6-8 and 21; The Limitations Act, S.S. 2004, c. L-16.1, ss. 5-7, Limitation of Actions Act, S.N.B. 2009, c. L-8.5, s. 5, Limitation of Actions Act, S.N.S. 2014 c. 35, s. 8; see also Bowes v. Edmonton (City), 2007 ABCA 347, 425 A.R. 123, at paras. 146-58).
 Further, absent legislative intervention, the discoverability rule applies only where the limitation period in question runs from the accrual of the cause of action, or from some other event that occurs when the plaintiff has knowledge of the injury sustained:In my opinion, the judge-made discoverability rule is nothing more than a rule of construction. Whenever a statute requires an action to be commenced within a specified time from the happening of a specific event, the statutory language must be construed. When time runs from “the accrual of the cause of action” or from some other event which can be construed as occurring only when the injured party has knowledge of the injury sustained, the judge-made discoverability rule applies. But, when time runs from an event which clearly occurs without regard to the injured party’s knowledge, the judge-made discoverability rule may not extend the period the legislature has prescribed. [Emphasis added.]
(Fehr v. Jacob (1993), 1993 CanLII 4407 (MB CA), 14 C.C.L.T. (2d) 200 (Man. C.A.), at para. 22, cited in Peixeiro, at para. 37.)
 Two points flow from this statement. First, where the running of a limitation period is contingent upon the accrual of a cause of action or some other event that can occur only when the plaintiff has knowledge of his or her injury, the discoverability principle applies in order to ensure that the plaintiff had knowledge of the existence of his or her legal rights before such rights expire (Peixeiro, at para. 39).
 Secondly (and conversely), where a statutory limitation period runs from an event unrelated to the accrual of the cause of action or which does not require the plaintiff’s knowledge of his or her injury, the rule of discoverability will not apply. In Ryan, for example, this Court held that discoverability did not apply to s. 5 of the Survival of Actions Act, R.S.N.L. 1990, c. S-32, which stated that an action against a deceased could not be brought after one year from the date of death. As the Court explained (para. 24):The law does not permit resort to the judge-made discoverability rule when the limitation period is explicitly linked by the governing legislation to a fixed event unrelated to the injured party’s knowledge or the basis of the cause of action. [Emphasis added; citation omitted.]
By tying, then, the limitation period to an event unrelated to the cause of action, and which did not necessitate the plaintiff’s knowledge of an injury, the legislature had clearly displaced the discoverability rule (Ryan, at para. 27).
 In determining whether a limitation period runs from the accrual of a cause of action or knowledge of the injury, such that discoverability applies, substance, not form, is to prevail: even where the statute does not explicitly state that the limitation period runs from “the accrual of the cause of action”, discoverability will apply if it is evident that the operation of a limitation period is, in substance, conditioned upon accrual of a cause of action or knowledge of an injury. Indeed, clear statutory text is necessary to oust its application. In Peixeiro, for example, this Court applied the discoverability rule to s. 206(1) of the Highway Traffic Act, R.S.O. 1990, c. H.8, which stated that an action must be commenced within two years of the time when “damages were sustained” (para. 2). The use of the phrase “damages were sustained” rather than “when the cause of action arose” was a “distinction without a difference”, as it was unlikely that the legislature intended that the limitation period should run without the plaintiff’s knowledge (para. 38).
(b) The Statutory Scheme, and the Objects of Statutory Limitation Periods
 The application of discoverability to the limitation period in s. 36(4)(a)(i) is also supported by the object of statutory limitation periods. This Court has recognized that three rationales underlie limitation periods (M. (K.), at pp. 29-31), which courts must consider in deciding whether the discoverability rule applies to a particular limitation period. The first is that limitation periods foster certainty, in that “[t]here comes a time . . . when a potential defendant should be secure in his reasonable expectation that he will not be held to account for ancient obligations”(M. (K.), at p. 29). This concern must be balanced against the unfairness of allowing a wrongdoer to escape liability while the victim of injury continues to suffer the consequences (M. (K.), at p. 29). The second rationale is evidentiary: limitation periods are intended to help prevent evidence from going stale, to the detriment of the plaintiff or the defendant (M. (K.), at p. 30). Finally, limitation periods serve to encourage diligence on the part of plaintiffs in pursuing their claims (M. (K.), at p. 30).
 Consideration of these rationales for limitation periods affirms discoverability’s application here. Even recognizing that shorter limitation periods indicate that Parliament put a premium on the certainty that comes with a limitation statute’s function of repose (Peixeiro, at para. 34), balancing all of the competing interests underlying s. 36(4)(a)(i) weighs in favour of applying discoverability. The ability of plaintiffs to advance claims for loss arising from conduct contrary to Part VI of the Competition Act outweighs defendants’ interests in barring them, especially where such conduct is, as I have already noted, concealed from plaintiffs (Fanshawe, at para. 46) (such that the evidentiary rationale — that is, the concern about evidence going “stale” — has no place in the analysis). To hold otherwise would create perverse incentives, encouraging continued concealment of anti-competitive behaviour until the two-year limitation period has elapsed. It would therefore not only bar plaintiffs from pursuing their claims, but reward concealment that has been “particularly effective” (Fanshawe, at para. 49).
 Limitation clauses are statutory provisions that place temporal limits on a claimant’s ability to institute legal proceedings. The expiry of a limitation period has the effect of “extinguish[ing] a party’s legal remedies and also, in some cases, a party’s legal rights” (G. Mew, D. Rolph and D. Zacks, The Law of Limitations (3rd ed. 2016) (“Mew et al.”), at p. 3). As this Court explained in M. (K.) v. M. (H.), 1992 CanLII 31 (SCC), (1992) 3 S.C.R. 6, statutory limitation clauses reflect the balance struck by the legislature between three distinct policy rationales: granting repose to defendants, avoiding evidentiary issues relating to the passage of time, and encouraging diligence on the part of plaintiffs.