Ich kann keinen Titel mit 3 Zeichen verwenden

[dmitry_fedyuk (Dmitrii Fediuk)]

[codinghorror (Jeff Atwood)]

I believe you have to disable some other protections in site settings for that to work.

[featheredtoast (Jeff Wong)]

Try toggling the allow uppercase posts setting - I noticed that the example title is in all caps.

allow uppercase posts - Allow all caps in a topic title or a post body.