A few answers, you can take your pick from:

 - We aren't Ubuntu Forums, we're Ask Ubuntu.
 - The software the drives the two websites is different.
 - We don't use BBCode, we use [Markdown (see this link for formatting guides, including code)][1].

**tldr** For blocks of code, prepend the line with four spaces, for shorter blocks, wrap in `` (backticks).


  [1]: http://askubuntu.com/help/formatting