A rendering hint is just a map that let the effect know how it is expected to behave. For example, antialiasing-on tells the effect that it should apply antialiasing to the process.
Every single rendering hint is a map. All methods that accept rendering hints expects them to be at the end, so it can merge them easily.
If you are writing your own effect and you want to handle rendering hints, you can use
create-rendering-hint for creating a RenderingHints object from a collection of them. Beware that it expects rendering hints, not a collection of them.
For more info, please look at the RenderingHints documentation.