wp-calypso/client/assets/stylesheets/shared/mixins/_no-select.scss

@mixin no-select {
	-webkit-touch-callout: none;
	-webkit-user-select: none;
	-khtml-user-select: none;
	-moz-user-select: none;
	-ms-user-select: none;
	user-select: none;
}