Gustavo, good luck on your paper. I'm sure you will get many opinions but I will lead with mine; the American Welding Society codes and standards are extraordinarly important and not just to Americans. The American Welding Society Codes touch or have some impact on virtually every nation on earth.

Probably the most recognized code AWS D1.1 is of generic importance to welding as it is completely self-contained and may be used in a multitude of applications even though it is titled a "Structural Welding Code - Steel." It has sister standards of AWS D1.5 and D1.6 for Bridges and Stainless Steel, respectively.

I have only given examples of 3 of the AWS standards above but there are numerous others which are critical to industry; if I failed to mention the filler metal standards A5 series I would be remiss, you will find that ASME also uses these same standards under the name of SFA standards in their ASME Section II, Part C.

I could probably go on and on with the significance of these standards but will leave some room for others to post their opinions as well.

The D1.1 Structural Steel Welding Code is the most commonly used code, it is referred to in just about any project that will have welding as a part of it.

This code has multiple face of important to the welding community, for the engineer there are design criteria, for the contractor and welders the code maps the road for welder qualification and welding procedures. The contractor use parts of the code to assure their product is fabricated to industry standard, there is a short section on how repairs may be made. And the inspector uses the document to perform visual inspection and non-destructive testing.

That is just one code published by AWS.