For simple stuff, you can use PRE tags instead of CODE. If you need to post code with backticks, or embedded strings that look like HTML, I use a PowerShell function to escape the code before posting. See http://powershell.org/wp/forums-tips/ for more information, under “Format Your Code”. The function I mentioned is in this blog post, and if you add the code to your ISE profile, you can just press F7 to escape the current ISE window’s code and copy it to your clipboard for pasting into a thread on the forums.
That said, you may see some changes in the WordPress / bbPress plugins being used here at some point in the near future, to make it more friendly for PowerShell. Don posted about this yesterday (http://powershell.org/wp/2014/06/09/wish-list-better-code-formatting-in-the-forums-can-you-help/).
Edit: Nevermind, now the formatting in the blog post was screwed up too. Download it from TechNet instead.