The variable guides are found on the "Clinical Data" page. From the top menu choose the Data & Documentation tab and click the submenu option clinical. Then click the "Variable Guides" link to the right of the header "Clinical Data." The variable guides are an offline alternative to search/browse for looking at the variable documentation. There are three primary guides distinguished by sort algorithm: Variable name (VG_Varname.pdf), Form (VG_Form.pdf), and category (VG_CatSubcat.pdf). For a good introduction to the guides please click on the link Variable Guide Tutorial.