Does the term "estoppel" or "waiver" apply to the purposes of estoppel?

¹⁸ Although courts such as Liberty , supra , 194 Cal.App.4th 839, 123 Cal.Rptr.3d 498 have used the nomenclature of "waiver" (id. at p. 845, 123 Cal.Rptr.3d 498 ), we believe that "estoppel" more accurately describes the operative principles. (See City of Hollister v. Monterey Ins. Co. (2008) 165 Cal.App.4th 455, 486487, 81 Cal.Rptr.3d 72 [discussing distinction between "waiver" and "estoppel" and noting latter involves prejudicial reliance by the party asserting estoppel].)