I know that the cart sends the variable info to the custom payment module in $payment_parameters.
 
And that errors your custom module genreates you put into $error_message.
 
But what if your module, say via AVS checks, wants to place an order status. Say all passed AVS checks I want customer order status set to 'Pending' and an AVS check in module to set the customer order to 'Review'. Assuming I have already setup these order status types. What variable do I need to include this information in?
 

Also what other variables are there for us to work with in our custom modules?

Sorry wish you had REAL forums where we could edit messages.
 
To clearify. I want my module to be able to set customers to either 'Pending' or 'Review' depending on how thier AVS results are from my module.