What is the test for determining the meaning of a "usual and ordinary meaning" provision in a regulatory regulation?

In determining the intent of lawmakers, courts look first to the words of the provision, giving those words their "usual and ordinary meaning." (Cf. People v. Hull (1991) 1 Cal.4th 266, 271, 274-275, 2 Cal.Rptr.2d 526, 820 P.2d 1036; City of Santa Cruz v. Municipal Court (1989) 49 Cal.3d 74, 90, 260 Cal.Rptr. 520, 776 P.2d 222.) The principle also applies to regulators. "Administrative regulations are subject to the same rules of construction and interpretation that apply to statutes." (Organization of Deputy Sheriffs v. County of San Mateo (1975) 48 Cal.App.3d 331, 341, 122 Cal.Rptr. 210.) ¹³