Latex-Suite also recognizes certain commonly used LaTeX commands for the <F9> key. At the moment, the \bibliographystyle, \addtocontents and the \addcontentsline commands are recognized, although more will be added in the future. When you press the <F9> after such a command, Latex-Suite will prompt you with a list of arguments which make sense for the command.

This functionality is available for commands for which a global variable of the form g:Tex_completion_{<command>} is defined where <command> is the command name. This variable is a comma separated list of values which this command takes. For example, the argument to the \bibliographystyle command is commonly one of abbr,alpha,plain,unsrt. Therefore, Latex-Suite defines

let g:Tex_completion_bibliographystyle = 'abbr,alpha,plain,unsrt'

You can define your own completion variables in a similar manner for commands which you might use.