8chan

https://8chan.co/prog/

All good criticisms. I would say that the specifications include one unique BBCode tag used per character. So the maximum single-character markup would be:

{u}{o}{b}{i}{sup}{sub}C{/sub}{/sup}{/i}{/b}{/o}{/u}

The combination of SUP and SUB would be pointless, but foar technical reasons I will allow the combination to remain in effect.

Adding color coades brings up other issues. If I allow thoase, then what will the result of {red}{green}C{/green}{/red} be?