According to D1.1, Table 4.9 to be qualified in ALL (groove) positions on plate, you'll need to take a 3G(vert) and a 4G(overhead) position test(s).
According to Table 4.10 (1) Thickness qualified depends on thickness tested(ie. thickness up to 1" tested = qualified in thicknesses 1/8" through 2 times thickness tested; 1" tested and up = qualified for unlimited thicknesses).
(ie tested on 3/8" plate = qualified on thickness 1/8" - 3/4".)
For a copy of D1.1 you can order online here....
http://global.ihs.com/industry_stds.cfm?currency_code=USD&customer_id=21254C2B4E0A&shopping_cart_id=2825585B2D4B2048415B5D30240A&rid=AWS&lang_code=ENGL&org_group=AWSD
John Wright