<style>
@font-face {
    font-family: 'ok';
    src: url('./ok.svg') format('svg');
}
@font-face {
    font-family: 'bad';
    src: url('./bad.svg') format('svg'), url('./bad.otf') format('otf');
}
.ok  { font-family: 'ok',  'Courier New'; font-size: 200%; }
.bad { font-family: 'bad', 'Courier New'; font-size: 200%; }
</style>

<p class=ok> (ok.svg) This must not be rendered with Courier font</p>
<p class=bad>(bad.svg) This must not be rendered with Courier font</p>