Gherkin is a style of requirements definitions that is often used for acceptance criteria. We can turn these requirements directly into code, and QA can turn them directly into test cases. The Gherkin format is generally associated with BDD, and it is used in Dan North's original article on the subject.  

The Gherkin format is just as simple as the user story format. It consists of three parts: Given, When, and Then. 

Given <Context> 
 And Given <More Context> 
 When <Action> 
 Then <Result> 
 And Then <More Results>