D1.3 is the specification for structural sheet steel with a thickness of less than or equal to 3/16 inch, .0188 in., 4.8 mm.
D1.1 is the spec for structural steel greater than 3/16 in.
Welder Qualification requirements are in Section 4 of D1.1.
Section 2 of D1.1 covers the design of welded...