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RAWeb 1.1RAAM 1.1

Replacement mechanism

This term is defined by more than one standard, and the wording differs. Each definition below is the one that applies to that standard’s criteria.

Definition in RAWeb 1.1

Mechanism generally based on CSS, allowing the user to replace text with image of text and vice versa on the principle of style switcher. The mechanism can use a server-side scripting language or a client-side scripting language.

Criteria in RAWeb 1.1

Definition in RAAM 1.1

A replacement mechanism is a feature that allows the user to access a version of the application with certain parameters (usually display parameters) modified (for example, font and background colours).

This mechanism may be provided by the platform itself or by the application. Where the platform has a robust replacement mechanism, authors should use it instead of an application-specific replacement mechanism.

Platforms offer users several replacement mechanisms. The activation of these replacement mechanisms is detectable by the applications, which can in turn serve specific information and presentations.

Replacement mechanisms available in iOS
  • Increase contrast: The option is available from the path: Settings > Accessibility > Display & text size > Increase contrast. When enabled, this option allows different styles to be loaded that have been defined by the author for this specific option in order to offer a higher contrast version to users who need it. In addition, this option increases the contrast of native iOS components such as switch buttons.
  • Differentiate without colour: This option is available via the path: Settings > Accessibility > Display & text size > Differentiate without colour. When enabled, this option allows you to load additional visual information other than colour (for example, shape or size) that has been defined by the author for this specific option, in order to highlight a graphic element whose colouring carries information (an active button, for example).
Replacement mechanisms available on Android

There are no replacement mechanisms in Android that are equivalent to those in iOS, or that are sufficiently robust.

The replacement mechanism available on Android ("High contrast text") is still experimental. Its use is not currently recommended.

Other replacement mechanisms not provided by the platforms

n If the platform does not provide a replacement mechanism for certain parameters, the application can provide one from its interface.

Criteria in RAAM 1.1