Primary actor: A description of the user who drives the operations outlined by the use case. The description of the primary actor can include things such as the role of the user (e.g. anonymous, basic, administrator, etc.) as well as characteristics of the user that may be relevant to how they interact with the application (e.g. age, disabilities, etc.)

Preconditions: Those conditions that must be met for the use case to proceed.

Main success scenario: A more granular, step-based description of the way the application works than is given in the basic or casual formats.

Alternative scenarios: More granular, step-based descriptions of the ways the application will handle alternative uses than are given in the casual format.

Special requirements: A list of requirements for the use case that don’t fit as part of the main or alternative scenarios.

Open issues: A list of notes including questions that must be answered to fully implement a solution for the use case.
Bibliograph:

Advanced ActionScript 3 with Design Patterns, By Joey Lott, Danny Patterson