Your specific development situation will determine which of the preceding methods is used. It is acceptable to provide end users with double links to the same application: one with accessibility enabled, another without. Developers may also opt to implement a check for an assistive technology device on the client system and redirect the user to an accessible version as needed.
There are additional considerations for some components. For example, it may be necessary to describe a component, make it silent, hide children of a component, assign a reading order, or create a shortcut key. To modify accessibility properties that apply to the entire document, create or modify the AccessibilityProperties object. Use the tabIndex property to determine the order in which objects receive input focus when users press the Tab key. The tabIndex property can also control the order in which a screen reader reads information about the object (known as the reading order).
For information about Flex 4 component behavior for keyboard and screen reader users, refer to the "Accessible components and containers" document in the Flex 4 Developer's Guide.