Here are the paragraphs with the word "gouging" from Sec IX. These paragraphs are referenced by other sections of the code. There are no requirements in Section IX or D1.1 to qualify gouging.
QW-401.4 Nonessential Variable (Procedure).
A change in a welding condition which will not
affect the mechanical properties of a weldment
(such as joint design, method of back gouging or
cleaning, etc.)
For vessels or parts of vessels constructed with
P-No. 11A and P-No. 11B base metals, weld grooves
for thickness less than 5/8 in. (16 mm) shall be
prepared by thermal processes when such processes
are to be employed during fabrication. This groove
preparation shall also include back gouging, back
grooving, or removal of unsound weld metal by
thermal processes when these processes are to be
employed during fabrication.
A change in the method of back gouging.
Have a nice day
Gerald Austin
http://weldingdata.com/