A more thorough explanation:

Ambiguitas patens is a type of ambiguity that is clear and obvious from the language used in a document. This means that there is a lack of clarity or uncertainty in the meaning of a word or phrase that is written down. For example, if a contract states that a product will be delivered on "Monday," but does not specify which Monday, this creates a patent ambiguity. The meaning of the word "Monday" is unclear and could refer to any Monday. This type of ambiguity is different from latent ambiguity, which is not immediately apparent from the language used in a document.