The exception for an ambiguity turns on whether the ambiguity is latent or patent. A latent ambiguity is one where the terms of the will are definite but that term could yield more than one meaning because of facts not showing on the face of the instrument. An example of the latent ambiguity would be a bequest to “John Doe” without any further identification where extrinsic evidence would be required to determine which John Doe was intended for the bequest. A patent ambiguity is one arising from an apparent contradiction within the document or where a term is used in the document that could yield several meanings. Obviously, in the example of the latter case the line between patent and latent ambiguity is fine:
That a latent ambiguity does not exist in the provisions of Roberts’ will is equally clear. Such an ambiguity occurs when “the language of the will is plain and single, yet is found to apply equally to two or more subjects or objects.” Darden v. Bright, 173 Md. 563, 569, 198 A. 431 (1938). Extrinsic evidence is generally admissible to resolve a latent ambiguity. Monmonier v. Monmonier, 258 Md. 387, 390, 266 A.2d 17 (1970); Bradford v. Eutaw Savings Bank, 186 Md. 127, 136, 46 A.2d 284 (1946); Fersinger v. Martin, supra, 183 Md. at 138-39, 36 A.2d 716; Darden v. Bright, supra, 173 Md. at 569, 198 A. 431; Cassilly v. Devenny, 168 Md. 443, 449, 177 A. 919 (1935). Indeed a latent ambiguity is “not discoverable until extrinsic evidence is introduced to identify the beneficiaries or the property disposed of by will, when it is developed by such evidence, either that the description in the will is defective, or that it applies equally to two or more persons or things.” 4 W. Bowe & D. Parker, Page on the Law of Wills § 32.7, p. 255 (rev. ed. 1961).
If the ambiguity, however, is latent then the extrinsic evidence may come in.