To obtain maximum benefit, may I suggest you use the "Search" facility provided by Rolf. I entered "PCN vs ASNT" and last month's lengthy debate on the very subject of your interest was indicated. Type in "certification" and you will get over 20 pages of links.
I hope that the quality and integrity of your work will play a bigger role in your future employment than through which system you are certified. At least, you could make that your goal to become the best NDT technician in Malaysia.