Carousel & Recent Listing Queries

Where can I find a list of the options that can be used in the Home Page Carousel and Recent Listings functions? The help button links to the Codex page for Function Reference/query posts, but that is not helpful I would like a list of the options specific to these features. For example :
What are the options to use in place of the word featured in this query:
orderby=meta_value&meta_key=featured
I’ve searched the forum, but am only getting a few options specific to the question being asked.