As there is no html field for small customizations I use sometimes the textarea. It works fine with most tags. Even <buttons> are displayed correctly. But the onclick event is lost during the php generation.

<button style="margin: 7px; padding: 7px;" onclick="sw_button('wahlprogramm2020/')">Programm Simmerath</button>

becomes

<button style="margin: 7px; padding: 7px;">Programm Simmerath</button>

Is there a solution. A html field would be very helpful.