RSACi effectively blocks unwanted content in four areas: Language, Nudity, Sex, and Violence.
Clicking on one of the key icons allows you to move the Rating slider in the middle of the window.
Leaving the slider for a given category all the way at the left will produce a Level 0 rating. This means that if a web pages content is anywhere above 0 it will be blocked.
If you would like to set the controls to be more lenient, move them over to the right. Pay attention to the descriptions as they are telling you what you are to block.
Clicking on the More Info button will bring you to this website and show a lengthy description of the RSACi Ratings Standard.