When you trying paste some text with "§" into name of world or serwer, text will appear without "§". It was avitable in previous versions. Also typing with left alt doesn't work, for example Left ALT + 0167 or left ALT + 21, what in text editors would give us "§".
Linked issues
Comments
For world and server names, you can edit the language pack to have something like "§6§6§6New World", so that you can use the arrow keys to get caret in between the § and the 6, which will make it visible. Then you can delete the 6, and use what ever code you want.
Unfortunately, intended duplicate of MC-1572
While § is used in the game to have formatting codes, it's not supported directly in the game. 😞