Definitions for "Complex script"
script with any of the following properties: Allows bidirectional rendering. Has contextual shaping. Has combining characters. Has specialized word-breaking and justification rules. Filters out illegal character combinations. Is not supported in the core Windows fonts and therefore may require font fallback. In some complex scripts, the order of the glyphs may be quite different from the order of the underlying Unicode characters they represent. See About Complex Scripts for more detail. Note In the context of typography, it is sometimes desirable to handle even the Latin script used in writing English as if it were a complex script. Examples include the Stylistic Alternates feature described in the documentation of OPENTYPE_FEATURE_RECORD, or ligatures, such as "fi", where a single glyph represents two or more consecutive characters.
Writing system based on characters that are composed of multiple glyphs or whose shape depends on adjacent characters. Thai and Arabic use complex scripts. See also glyph.
a script characterized by one or more of the following: a very large set of characters, right-to-left or vertical rendering, bidirectionality, contextual glyph selection (shaping), use of ligatures, complex glyph positioning, glyph reordering, and splitting characters into multiple glyphs.