Ideographic Description Characters is a Unicode block containing graphic characters used for describing CJK ideographs. They are used in Ideographic Description Sequences (IDS) to provide a description of an ideograph, in terms of what other ideographs make it up and how they are laid out relative to one another. An IDS provides the reader with a description of an ideograph that cannot be represented properly, usually because it is not encoded in Unicode; rendering systems are not intended to automatically compose the pieces into a complete ideograph, and the descriptions are not standardized.
U+2FF0 to U+2FFB were introduced from GBK; U+2FFC to U+2FFF were devised later and introduced in Unicode 15.1 (2023).
Ideographic Description Sequences are sequences of characters that represent a Chinese character structure as defined by the Unicode standard.
Below are the 16 characters as defined by Unicode in this block:
Two other related ideographic description characters are not encoded in this Unicode block, but of which may be used in ideographic description sequences:
There is also the character "â¬Â", encoded as U+2B1A. Although its name is simply "dotted square", it is frequently used alongside ideographic characters to denote indivisible, complete units.
This is the syntax of IDS in EBNF:
The following Unicode-related documents record the purpose and process of defining specific characters in the Ideographic Description Characters block: