Unicode compatibility characters: Difference between revisions

Revision as of 05:20, 23 March 2018

Revision as of 23:41, 9 June 2018

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=== Rich text compatibility characters ===

Many other compatibility characters constitute what Unicode considers rich text and therefore outside the goals of Unicode and UCS. In some sense even compatibility characters discussed in the previous section — those that aid legacy software in displaying ligatures and vertical text — constitute a form of rich text, since the rich text protocols determine whether text is displayed in one way or another. However, the choice to display text with or without ligatures or vertically versus horizontally are both non-semantic rich text. They are simply style differences. This is in contrast to other rich text such as italics, superscripts and subscripts, or list markers where the styling of the rich text implies certain semantics along with it.

For comparing, collating, handling and storing plain text, rich text variants are semantically redundant. For example, using a superscript character for the numeral 4 is likely indistinguishable from using the standard character for a numeral 4 and then using rich text protocols to make it superscript. Such alternate rich text characters therefore create ambiguity because they appear visually the same as their plain text counterpart characters with rich text formatting applied. These rich text compatibility characters include: