CSS Attribute Selectors

[attr] elements with an attr attribute
[attr=val] attr attribute equals val
[attr~=val] attr attribute contains val (does not select vals)
[attr|=val] attr value equals to val or starts with val-
[attr^=val] attr value starts with val (or is equal to val)
[attr$=val] attr value ends with val (or is equal to val)
[attr*=val] attr contains val

[exp i], where exp is one of the above expressions (without the brackets), makes the value selection case-insensitive.

[exp s] (experimental) selects the value with case-sensitivity.

Examples: [data-units i], span[title~="flag"]

Like other CSS selectors, multiple attribute selectors can be combined, e.g. a[href^="https"][href$=".png"].

reference