django: kwargs for Form()

def contact(request):
    if request.method == 'POST':
        form = ContactForm(request.POST, prefix='something-%s' % (some_id,), label_suffix=': ')
        if form.is_valid():
           pass
    else:
        form = ContactForm(prefix='something-%s' % (some_id,), label_suffix=': ')

    return render(request, 'contact.html', {
        'form': form,
    })