attr() - CSS: Cascading Style Sheets
note: the attr() function can be used with any css property, but support for properties other than content is experimental, and support for the type-or-unit parameter is sparse.
... <type-or-unit> is a keyword representing either the type of the attribute's value, or its unit, as in html some attributes have implicit units.
... if the use of <type-or-unit> as a value for the given attribute is invalid, the attr() expression will be invalid too.
...And 3 more matches

CSS data types - CSS: Cascading Style Sheets
le> <counter-style> <custom-ident> <dimension> <filter-function> <flex> <frequency> <frequency-percentage> <gradient> <ident> <image> <integer> <length> <length-percentage> <number> <number-percentage> <percentage> <position> <quote> <ratio> <resolution> <shape-box> <shape-radius> <string> <time> <time-percentage> <timing-function> <toggle-value> <transform-function> <type-or-unit> <url> <url-modifier> <zero> specifications specification status comment css values and units module level 4 editor's draft css values and units module level 3 candidate recommendation initial definition.

counter() - CSS: Cascading Style Sheets
note: the counter() function can be used with any css property, but support for properties other than content is experimental, and support for the type-or-unit parameter is sparse.

counters() - CSS: Cascading Style Sheets
note: the counters() function can be used with any css property, but support for properties other than content is experimental, and support for the type-or-unit parameter is sparse.