Indenting bullets in vim

The vim faq (Question 13.4 How do I format a bulleted and numbered lists) that vim can be configured to format bulleted and numbered lists. However, it only gives an example for numbered lists. For bullets (such as a *), the following settings must be changed:

set ai
set tw=20
set com=fb:*

ai sets auto indention. Make sure ai is set and paste toggled off
tw sets the text width. This is the position around which a newline will be inserted when typing
com sets the comments option. The star (*) in fb:* defines * to be a comment. The b in stipulates that there must be a blank after the comment. f says that only the first line needs the comment string. That is, when text width is reached and a new line is inserted (by vim), the * is not repeated.