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 (
- any decimal digit (
- 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)
ID1 are all different identifiers as they are case-sensitive. On the other hand, as there are several ways to escape a character,
toto\3F are the same 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
|CSS Values and Units Module Level 4 |
As this type is not a real type but a convenience type used to simplify the definition of other CSS syntax, there is no browser compatibility information as such.