For procedure qualification not much changes:
4.1 Structural (nonpressure boundary) welding requirements shall comply with either AWS D1.1 or AWS D1.6.
When approved by the purchaser (engineer) welding procedures may be qualified per ASME BPVC Section IX.
For fabrication purposes there are additional requirements that are not addressed by Section IX because Section IX isn't a building code. What welding processes are you using and what do you intend to use it for?