A searchable guide to the complete WordPress Icon Library (@wordpress/icons) package from Gutenberg.
import { Icon, cornerTopLeft } from '@wordpress/icons';
<Icon icon={cornerTopLeft} />
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" aria-hidden="true" focusable="false"><g opacity=".25"><path d="M5.75 6A.25.25 0 0 1 6 5.75h3v-1.5H6A1.75 1.75 0 0 0 4.25 6v3h1.5V6ZM18 18.25h-3v1.5h3A1.75 1.75 0 0 0 19.75 18v-3h-1.5v3a.25.25 0 0 1-.25.25ZM18.25 9V6a.25.25 0 0 0-.25-.25h-3v-1.5h3c.966 0 1.75.784 1.75 1.75v3h-1.5ZM5.75 18v-3h-1.5v3c0 .966.784 1.75 1.75 1.75h3v-1.5H6a.25.25 0 0 1-.25-.25Z"></path></g><path fill-rule="evenodd" clip-rule="evenodd" d="M6 5.75a.25.25 0 0 0-.25.25v3h-1.5V6c0-.966.784-1.75 1.75-1.75h3v1.5H6Z"></path></svg>
cornerTopLeft – WordPress Icon Library