I'd like to load a stylesheet when my URL variable contains "?view=full".
Is it possible to do this in HTML (i.e. not PHP)? If so, how?
It’s not possible in pure HTML; you'd have to use either PHP or JavaScript. If you want to do it in JavaScript, you could put this in your <head>
section:
<script>
if (window.location.search.indexOf('?view=full') === 0)
document.write('<link rel="stylesheet" href="theStylesheet.css" />');
</script>