The <ident> CSS data type denotes an arbitrary string used as an identifier.

nono79        A mix of alphanumeric characters and numbers ground-level  A mix of alphanumeric characters and a dash -test         A dash followed by alphanumeric characters --toto        A custom-property like identifier _internal     An underscore followed by alphanumeric characters \22 toto      A Unicode character followed by a sequence of alphanumeric characters bili\.bob     A correctly escaped period 

ident

The <ident> CSS data type denotes an arbitrary string used as an identifier.

Syntax

The syntax of <custom-ident> is similar to CSS identifiers (such as property names), except that it is case-sensitive. It consists of one or more characters, where characters can be any of the following:

any alphabetical character (A to Z, or a to z), any decimal digit (0 to 9), a hyphen (-), an underscore (_), an escaped character (preceded by a backslash, \), a Unicode character (in the format of a backslash, \, followed by one to six hexadecimal digits, representing its Unicode code point)

Note that id1, Id1, iD1 and ID1 are all different identifiers as they are case-sensitive. On the other hand, as there are several ways to escape a character, toto\? and toto\3F are the same identifiers.

Examples

Valid identifiers

nono79        A mix of alphanumeric characters and numbers ground-level  A mix of alphanumeric characters and a dash -test         A dash followed by alphanumeric characters --toto        A custom-property like identifier _internal     An underscore followed by alphanumeric characters \22 toto      A Unicode character followed by a sequence of alphanumeric characters bili\.bob     A correctly escaped period 

Invalid identifiers

34rem     It must not start with a decimal digit. -12rad    It must not start with a dash followed by a decimal digit. bili.bob  Only alphanumeric characters, _, and - needn't be escaped. 'bilibob' This would be a <string>. "bilibob" This would be a <string>. 

Specifications

Specification	Status	Comment
CSS Values and Units Module Level 4The definition of '<ident>' in that specification.	Editor's Draft
CSS Values and Units Module Level 3The definition of '<ident>' in that specification.	Candidate Recommendation

As this type is not a real type but a convenience type used to simplify the definition of other CSS syntax.

See also

<custom-ident> – A restricted subset of <ident> values excluding CSS-wide keywords, custom properties and other per-property values.

Last modified: Jan 25, 2022, by MDN contributors

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