Modalsuffixes

Modalsuffixes are a critical component in the development of Unicode characters, primarily used in non-English languages. They were first introduced in the Universal Character Set (UCS) version 4.0 in 1993. Modalsuffixes serve as a means to extend the character set by providing additional information about a character's properties.

These suffixes are used to indicate a character's directionality, depending on whether it is written from left to right or right to left. This is crucial in languages such as Arabic, Urdu, and Farsi, which read from right to left. Modalsuffixes provide a means to explicitly state the character's directionality, guiding text rendering engines and layout algorithms to properly display texts written in these languages.

Modalsuffixes are composed of a 'freestanding Combining Mark' and a character. They are added to a base character to indicate the character's properties. In many cases, the use of modalsuffixes is optional; however, they can be utilized to provide clear and unambiguous directionality information for characters.

Some notable examples of modalsuffixes include dot above, dot below, and right half ring. These suffixes are essential in the processing and rendering of non-English text. Implementing modalsuffixes in text rendering and layout engines helps to ensure accurate and consistent text display across languages and platforms.

The use of modalsuffixes has had a significant impact on the rendering and layout of non-English languages, particularly in the era of multipurpose keyboards, internationalized text processing and rendering, and multilingual resources.