First thing to know is that all of these fields are optional. RV Type gives you a drop down box with common types and standard descriptions of RVs to choose from. If you want only truck campers or fifth wheels (etc.) use this box. The year field allows you to set a range of model years. To look at just one model year, enter the year in both boxes. Manufacturer lets you type the makers name in. Price range is self explanatory, prices are in U.S. Dollars. Keyword is a helpful feature and many find they use just the keyword search. Type in a manufacturer name or special feature and the search will look for all ads that include those words.