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CSS/tactile braille and haptic

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Add haptic Media Type to the tactile Media Group


  • tactile is defined as "capable of, allows for being touched"
  • tactual is defined as "arising from or due to touch";

The definition of "tactual" corresponds to that portion of the tactile media group, which -- in order to differentiate it from braille -- is defined as material perceived by the sense of touch which requires no prior knowledge in order to be correctly perceived;

Having researched the meaning of the terms "tactile" and "tactual", "tactual" is the term which best expresses the difference between tactual media (which is intended to be conveyed via touch, but which requires no previous knowledge and does not represent a natural language), and braille, which is a tactile representation of a specific natural language (as well as specific natural language instances if the braille device being used supports natural language switching on-the-fly);


Janina Sajka pointed out that the words "tactile" and "tactual" are extremely similar in sound and overlap in meaning; it has been suggested by Stefan Schnabel that "tactual" be called "haptic"


There is precedent for the separation of "braille" from "haptic" as discrete media types, in that "audio" and "speech" are treated as discrete concepts. So, too, should "braille" and "haptic" be treated as the separate-but-related concepts they are. There is great room for flexibility in this realm, as braille stylesheets are -- for the most part, if not entirely -- theoretical constructs, despite the Braille Stylesheets Preliminary Requirements Analysis.


"tactile" as a media group covers both braile and tactual media, as both convey information through the sense of touch; therefore, it is proposed:

  1. CSS retain the media group "tactile";
  2. CSS add a new media type to the tectile media group, "haptic", to cover tactile media is not a representation of a natural language

For Reference

CSS 2.1 defines the following media groups:

  • continuous or paged.
  • visual, audio, speech, or tactile.
  • grid (for character grid devices), or bitmap.
  • interactive (for devices that allow user interaction), or static (for those that do not).
  • all (includes all media types)

CSS 2.1 defines the following media types:

  • braille
  • embossed
  • handheld
  • print
  • projection
  • screen
  • speech
  • tty
  • tv

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