Read this: No one party to a treaty can impose its particular interpretation of the treaty upon the other parties. Consent may be implied, however, if the other parties fail to explicitly disavow that initially unilateral interpretation, particularly if that state has acted upon its view of the treaty without complaint. Consent by all parties to the treaty to a particular interpretation has the legal effect of adding another clause to the treaty – this is commonly called an 'authentic interpretation'.

Consent by all parties to a treaty to a particular interpretation of the treaty has what legal effect?
What is the answer? (If it cannot be answered, return "unanswerable")
adding another clause to the treaty