Sorry, this article is only available in German.
It covers the following topics you should consider for a good website:
- Use valid HTML.
- Keep URLs available – if needed, forward old URLs to the new ones, but don’t just remove them (also see https://www.w3.org/Provider/Style/URI).
- Barrier free layout – size of text and elements containing text should always use the unit “em”, the length of text lines should have a maximum width, content should be usable on every kind of device, avoid links to the current URL.