SC1-1-1-character-based-non-textual

Status

Description

This test checks that no non-textual information is conveyed by a sequence character.

Background

• H86: Providing text alternatives for ASCII art, emoticons, and leetspeak
• F72: Failure of Success Criterion 1.1.1 due to using ASCII art without providing a text alternative
• WAI: ASCII art detection algorithms

Assumptions

• ASCII art can be assembled using every printable character
• ASCII art can be multiline
• The charset is specified in the head section
• The font used can be either a system font or a font retrieved from the web
• Some characters are adjacently repeated more than 4 times
• Most ASCII art uses non-letter characters
• Most ASCII art is inside pre or xmp elements (could also be a CSS white-space: pre styled element)
• Most ASCII art uses MonoSpace-fonts

• Text used to form shapes conveying information is also considered to be ASCII art

• Leetspeak is built following a set fixed rules and can be translated and also detected.
• Emoticons are built following a set fixed rules and can be translated and also detected.

• Single unicode characters in private use area U+E000 to U+F8FF can be used to display graphics. Even those can convey information, e.g. be an icon for a filetype

Test properties

Test procedure

Selector

All text nodes with exception of those contained in script and style elements
//*[not(self::script or self::style)]/text()

Step 1