The rule about admission or exclusion of extrinsic evidence has been laid down under section 93 to 98 of the Indian Evidence Act. Such exclusion or admission of extrinsic evidence is in connection with the facts contained in a document which either a contract or not.
The ambiguity in the language of a document can be divided into two categories:
- Patent ambiguity
- Latent ambiguity
A patent ambiguity is when the language of the document or deed is uncertain. The latent ambiguity is an ambiguity which is not present in the deed but it arises due to extrinsic factors.
Test of difference
The test to find the difference that whether the ambiguity is a patent ambiguity or a latent ambiguity is to put the document in the hands of an ordinary intelligent educated person.
- If on reading the document the ambiguity can be detected and no definite meaning can be understood then such ambiguity is patent ambiguity.
- If on perusal of document no ambiguity can be found by him and the meaning is definite but that document is applied with the instrument of facts, the ambiguity arises and its meaning becomes indefinite, then the ambiguity is the latent ambiguity.
The distinction between Patent Ambiguity and Latent Ambiguity
| S.No. | Patent Ambiguity | Latent Ambiguity |
| 1. | When the language of the document is so uncertain and effective that no meaning can be granted to the document then it is called as Patent Ambiguity. | When the language of a document is certain and meaningful but the document makes no relevance in the present circumstance then it is latent ambiguity. |
| 2. | The patent ambiguity is personal in nature and it is related to the person executing the document. | The latent ambiguity is of objective nature and it is related to the subject matter and object of the document. |
| 3. | Oral evidence is not allowed for the removal of patent ambiguity. | To remove latent ambiguity, oral evidence is allowed. |
| 4. | The rule on which the patent ambiguity is based is that the patent ambiguity makes the document useless. | Giving oral evidence in case of latent ambiguity is based on the principle the latent ambiguity does not make a document useless. |
| 5. | A patent ambiguity is on the face of the document and is evident from inspection of the document itself. | Latent ambiguity is not evident from prima facie inspection of the document but it becomes apparent when the language of a document is applied to existing circumstances |