Per https://www.w3.org/TR/css-masking-1/#clip-property, https://developer.mozilla.org/en-US/docs/Web/CSS/clip and https://caniuse.com/mdn-css_properties_clip, the clip property is deprecated.
Should probably add some future-proof CSS via clip-path per https://caniuse.com/css-clip-path, https://developer.mozilla.org/en-US/docs/Web/CSS/clip-path but also add -webkit-clip-path to support Safari <9.1 released 03/2016 and Chrome <55 released 12/2016.
Plus keep deprecated clip to support Opera <42 released 12/2016 and Edge <78 released 01/2020.
[acko@foo phorge (master $|u=)]$ grep -r " clip:" --include=*.css . ./webroot/rsrc/css/font/font-awesome.css: clip: rect(0, 0, 0, 0); ./webroot/rsrc/css/font/font-awesome.css: clip: auto; ./webroot/rsrc/css/core/core.css: clip: rect(1px, 1px, 1px, 1px); ./webroot/rsrc/css/core/core.css: clip: auto;