Index of predominant national and selected regional or minority scripts

Alphabetic [L]ogographic and [S]yllabic Abjad Abugida   Latin   Cyrillic   Greek   Armenian   Georgian   Hangul a   Hanzi [L]   Kana [S] / Kanji [L]     Hanjab [L]   Arabic   Hebrew   North Indic   South Indic   Ethiopic   Thaana   Canadian syllabic

a Featural-alphabetic.   b Limited.

Character reference overview

An HTML or XML numeric character reference refers to a character by its Universal Character Set/Unicode code point, and uses the format

&#nnnn;

or

&#xhhhh;

where nnnn is the code point in decimal form, and hhhh is the code point in hexadecimal form. The x must be lowercase in XML documents. The nnnn or hhhh may be any number of digits and may include leading zeros. The hhhh may mix uppercase and lowercase, though uppercase is the usual style.

In contrast, a character entity reference refers to a character by the name of an entity which has the desired character as its replacement text. The entity must either be predefined (built into the markup language) or explicitly declared in a Document Type Definition (DTD). The format is the same as for any entity reference:

&name;

where name is the case-sensitive name of the entity. The semicolon is required.

Unicode blocks

In Unicode, a block is defined as one contiguous range of code points. Blocks are named uniquely and have no overlap. They have a starting code point of the form hhh0 and an ending code point of the form hhhF. A block explicitly can include code points that are unassigned and non-characters.^[1] Code points not belonging to any of the named blocks, e.g. in the unassigned planes 3–13, have the value block="No_block".

Conversely, every assigned code point has a property "Block name", which names in which block the character is. This is determined by the code point only, although a block name will have a descriptive nature: "Tibetan" or "Supplemental Arrows-A". All assigned code points have a single block name.

Subdivisions, such as "Chess symbols" in the block Miscellaneous symbols, are not a "block". The subgroup name is an informative editorial addition only.

The number of code points in a Unicode block is a multiple of 16. Unicode blocks range in size from the minimum of 16 to a maximum of 65,536 code points.

Unicode 9.0 defines 273 blocks:^[2]

• 161 in plane 0, the Basic Multilingual Plane (BMP)
• 103 in plane 1, the Supplementary Multilingual Plane (SMP)
• 5 in plane 2, the Supplementary Ideographic Plane (SIP)
• 2 in plane 14 (E in hexadecimal), the Supplementary Special-purpose Plane (SSP)
• One each in planes 15 (F_hex) and 16 (10_hex), called Supplementary Private Use Area-A and -B

See also

• Scripts in Unicode

References

1. ^ Unicode glossary
2. ^ Unicode 9.0.0 UCD

External links

• Official web site of the Unicode Consortium (English)