Topic on Project:Support desk

For more readability I would like to reduce my content width after the TOC. So I need to add html code after the TOC. What is the easiest way to do that?

I checked the available hooks but didn't find anything that is suitable.

Why do you want to change the HTML? This is a CSS issue. You should fix this by adding your styles to the wiki page MediaWiki:Common.css in your wiki.

I was not precise enough: I would like to add some divs to generate a two-column-layout. But this should only start below the TOC. So I need to add html there.

Better add templates to your pages, like this:

Intro here __FORCETOC__ {{TwoColumns | 1=Text goes here ... }}

Good idea FriedhelmW, thanks.
For my content I think I'll need two different SemanticForms fields then instead of one: One for the intro - and one for the rest of the content.