Allowed markup: a blockquote br code em (which in html is a unit of measurement of text) strong ul ol li.
Put actual snippets of code in between `backticks` (i.e., the code you want people to see, the litteral code and not what is produced by the code).
a - used to insert live links or an 'anchor' (URLs) - equivalent of the [url] tag in bbCode
blockquote - for quoting test - equivalent of the [quote] tag in bbCodebr - for line-breaks - no need to it in bbCode
code / ` - to wrap codes - equivalent of the [code] tag in bbCode
text - equivalent of the [I] tag in bbCode
strong - for bold text - equivalent of the [B] tag in bbCode
ul / ol / li - for unordered lists - equivalent of the [list] / [*] tag in bbCode
In bbpress: instead of the [ & ] brackets used in bbCode, in HTML and so in bbPress < & > (lessThan and greaterThan) are used to 'encapsulate' the element (code).

You Type

You see

• List Item
• List Item

1. List Item
2. List Item

1. List Item
2. List Item

1. List Item
2. List Item

$this_var = "Hello World!";