The general rule of will construction, that extrinsic evidence of a testator’s intent is not admissible, but that such testimony related to the settlor’s intent in an inter vivos trust may be admissible, has a ripple effect. Generally, testamentary trusts are not to be modified due to mistake or to more fully comport with the settlor’s intent which is not the rule for inter vivos trusts: “[T]he doctrine of (trusts) reformation is ordinarily applicable only in cases … involving inter vivos trust instruments. Here we are confronted with a testamentary trust and … the general prohibition against reformation of a will would prevail.” This non-reformation rule as to wills or testamentary trusts, as distinct from the treatment of nonprobate transfers, is universal under the common law:
The no-reformation rule is peculiar to the law of wills. It does not apply to other modes of gratuitous transfer – the so-called nonprobate transfers – even though many are virtually indistinguishable from the will in function. Reformation lies routinely to correct mistakes, both of expression and of omission, in deeds of gift, inter vivos trusts, life insurance contracts, and other instruments that serve to transfer wealth to donees upon the transferor’s death. Alternatively, courts sometimes find it necessary to remedy mistakes in these nonprobate transfers by imposing a constructive trust on the mistakenly named beneficiary in favor of the intended beneficiary.
The general rule of construction for wills is, of course, the plain meaning rule. Courts are to tease out the meaning from the four corners of the will without resort to extrinsic evidence, including extrinsic evidence from the drafter of the document:
And the evidence of the draftsman of the will is not offered to contradict the will. In the case of Fersinger v. Martin, 183 Md. 135, on page 138, 36 A.2d 716, at page 718, this Court, speaking through Judge Collins, said, ‘The general rule is that no expression as to the intention of the testator may be considered for the reason that an oral utterance would not be a compliance with the statutory requirement that the will be in writing. Miller on Construction of Wills, Section 40; Darden v. Bright, 173 Md. 563, 568, 198 A. 431. We cannot resort to extrinsic evidence to ascertain from the draftsman what the testator instructed or intended him to say, nor can we in order to establish the intention of the testator accept his declarations.’ See also Board of Visitors, etc., v. Safe Deposit & Trust Co., Md., 46 A.2d 280. The testimony of the draftsman is, therefore, clearly inadmissible to show what the testator intended by Paragraph II. A testator cannot be heard to say what were his intentions in putting a certain clause in his will, and his attorney, who drafted the will, cannot say what the testator told him about it unless there is a latent ambiguity in the words of the will. No such ambiguity exists here.
The essential irrationality of the plain meaning rule has been long noticed:[W]e think that there is no principled way to reconcile the exclusion of extrinsic evidence in the law of wills with the rule of admissibility in the law of nonprobate transfers. Not surprisingly, the no-extrinsic-evidence rule has long been embattled even in the traditional law of wills; it has been subjected to a variety of exceptions, some of which we discuss below in part II; and it is now on the decline. Wigmore’s immensely influential critique of the no-extrinsic-evidence rule underlies its abrogation in California and New Jersey. Wigmore argued that any effort to limit the proofs to the words of a document runs afoul of the “truth … that words always need interpretation ….” Wigmore coined the famous phrase that “the ‘plain meaning’ … is simply the meaning of the people who did not write the document.”
There is no surer way to misread any document than to read it literally; in every interpretation we must pass between Scylla and Charybdis; and I certainly do not wish to add to the barrels of ink that have been spent in logging the route. As nearly as we can, we must put ourselves in the place of those who uttered the words, and try to define how they would have dealt with the unforseen situation; and, although their words are by far the most decisive evidence of what they would have done, they are by no means final.
 Shriners Hospital for Crippled Children v. Maryland Nat. Bank, 270 Md. 564, 581-2, 312 A.2d 546, 555 (1973).
 John H. Langbein & Lawrence W. Waggoner, Reformation of Wills on the Ground of Mistake: Change of Direction in American Law?, 130 U. Pa. L. Rev. 521, 523 (1982).
 Bradford v. Eutaw Sav. Bank of Baltimore City, 186 Md. 127, 135-6, 46 A.2d 284, 288 (1946).
John H. Langbein & Lawrence W. Waggoner, Reformation of Wills on the Ground of Mistake: Change of Direction in American Law?, 130 U. Pa. L. Rev., page 526 (1982).
 Guiseppi v. Walling, 144 F.2d 608, 624 (2d Cir. 1944) (Learned Hand in a concurring opinion.)