A Test Case is defined as having the following fields:

Number, abbreviated to No., and is the number of the test case in the table or document.
Heading. A useful short description of the test case.
Description. A summary of the test case.
ID. An alphanumeric identifier, unique to the test and derived from the element under test and the number field.
Prerequisites. Describes the preconditions needed for the tests to be executed.
Test Steps. This is a series of at least 3 steps that clearly describes how to execute the test case. Each step shall be numbered.
Expected Results. This describes the expected outcomes for each of the steps itemised in Test Steps.