(4) We shall assume, without deciding, that knowledge of a unilateral mistake imputed to a party from his properly authorized agent would be a sufficient basis for reformation. (See Stare v. Tate, 21 Cal.App.3d 432, 437 [ 98 Cal.Rptr. 264] ; but cf. Ward v. Yorba, 123 Cal. 447, 450 [56 P. 58].) Nevertheless, the argument that Lawyers Title's knowledge of the land use restriction is imputed to defendants is not meritorious.

When a contract is reformed on grounds of unilateral mistake, the contract which was intended by the party acting under that unilateral mistake is the contract of the parties (provided no third parties are prejudiced thereby). See Cal. Civ. Code Section 3399; Stare v. Tate, 21 Cal.App.3d 432, 438-439; 98 Cal.Rptr. 264, 268 (1971); Eagle Indem. Co. v. Industrial Accident Commission, 92 Cal.App.2d 222, 229; 206 P.2d 877, 881 (1949); Hanlon v. Western Loan Bldg. Co., 46 Cal.App.2d 580, 603; 116 P.2d 465, 478 (1941) (reformation of deed). Here, no third parties were or will be prejudiced.

The "net value" refers to the community estate's equity in the property. (See Stare v. Tate (1971) 21 Cal.App.3d 432, 435 ["equity" or "net value" calculated as gross value less encumbrances].)

Finally, "[a]lthough a court of equity may revise a written instrument to make it conform to the real agreement, it has no power to make a new contract for the parties, whether the mistake be mutual or unilateral [citation]." ( Shupe v. Nelson (1967) 254 Cal.App.2d 693, 700 [ 62 Cal.Rptr. 352] ; Stare v. Tate (1971) 21 Cal.App.3d 432, 438 [ 98 Cal.Rptr. 264].) Here, the evidence offered by Appalachian in support of reformation consists of (1) statements by the parties prior to the incorporation of article 14 into the contract of their intent to comply with the interparty waiver NASA would require in the launch services agreement, and (2) the variance in the scope of the interparty waiver required by NASA in the launch services agreement (i.e., waivers of liability between NASA and the space shuttle customers and their respective contractors and subcontractors and among the space shuttle customers and their contractors and subcontractors) and the scope of the waiver contained in article 14 (i.e., waivers not only among Western Union and its contractors and subcontractors, NASA and other space shuttle customers but also waivers between Western Union and McDonnell Douglas and McDonnell Douglas's contractors and subcontractors).

And there is no requirement to pick over the minute details and calculations contained in settlement correspondence to be sure it does not contain a mistake by the other side. Nevertheless, the law provides for rescission when a party knows of his adversary's mistake, and then conceals it to his own advantage. Stare v. Tate, 21 Cal.App.3d 432, 439-40, 98 Cal.Rptr. 264, 268-69 (1971) (Kaus, J.). Even in the less compelling case in which the party ought to be aware of the adversary's mistake, the law permits rescission.

In such situations, reformation is possible because the nondisclosing party is deemed to have intended to enter into the agreement sought by the aggrieved party; the nondisclosing party is estopped to deny the existence of this agreement. La Mancha Dev. Corp. v. Sheegog, 78 Cal.App.3d 9, 16, 144 Cal.Rptr. 59 (1978); Stare v. Tate, 21 Cal.App.3d 432, 438, 98 Cal.Rptr. 264 (1971). See also Cal.Civ.Code §§ 3399, 3400.

In such situations, reformation is possible because the nondisclosing party is deemed to have intended to enter into the agreement sought by the aggrieved party; the nondisclosing party is estopped to deny the existence of this agreement. La Mancha Dev. Corp. v. Sheegog, 78 Cal.App.3d 9, 16, 144 Cal.Rptr. 59 (1978); Stare v. Tate, 21 Cal.App.3d 432, 438, 98 Cal.Rptr. 264 (1971). See also Cal.Civ. Code §§ 3399, 3400.

A party who enters into a contract knowing that the other party has a particular understanding of its meaning may be required to accept the other party's interpretation. (See § 3399 ["When, through . . . a mistake of one party, which the other at the time knew or suspected, a written contract does not truly express the intention of the parties, it may be revised on the application of the party aggrieved, so as to express that intention"]; Stare v. Tate (1971) 21 Cal.App.3d 432, 438 ["The law . . . estops the party who knows of the plaintiff's mistake from claiming that his intent differs from what he leads the other to believe it is"].) Although Appellants have not requested the remedy of contract reformation, the alleged facts could support such a theory.

Because Notrica and SCIF previously had operated under a different guideline, SCIF had a duty to disclose and explain "maximum probable potential cost" and not to mislead Notrica into believing there had been no change. ( Goodman v. Kennedy (1976) 18 Cal.3d 335, 347 [ 134 Cal.Rptr. 375, 556 P.2d 737]; Warner Constr. Corp. v. City of Los Angeles (1970) 2 Cal.3d 285, 294 [ 85 Cal.Rptr. 444, 466 P.d 996]; Eddy v. Sharp (1988) 199 Cal.App.3d 858, 864-865 [ 245 Cal.Rptr. 211]; Stare v. Tate (1971) 21 Cal.App.3d 432, 438-440; Ins. Code, § 330.) SCIF's "Sales Techniques" document provides that when a potential customer indicates an understanding that SCIF over-reserves, there are four responses, including: "Let's look at that based on the way you estimate your costs.