Wills, Trusts, and Estates
Ambiguities can be either patent or latent.
External evidence is admissible to resolve patent ambiguities under modern law, but not under common law.
A latent ambiguity is one that only arises when applied to the facts. E.g., it says to give it to someone but there are two people by that name.
Latent ambiguities can be between exact fits or partial fits.
E.g., if you have a friend named Jeanilee, but you exclusively and oddly call her "Vicky" in your folly, extrinsic evidence would be admitted to resolve who Vicky is.