I am using AutoCAD as my drawing tools for almost 3 years now but still i don't know the pen assignment standard and line weight. is there somebody out there who can help me?tnx! 

Standards are usually created by the organization you're working for or they may be based on your locale. Being that you're in the Philippines, most here probably won't know the standards in your area.You can, however, check with someone in your area who may have more experience to see if they know of any standards. To set (or get) your 'Plot Style Table Settings', you can either start in your plot window or your Options (OPTIONS, CONFIG, PROPERTIES) and click on the 'Plot Style Table Settings...' button.Good Luck!!

I guessed you already knows that i am not a member of any organization the way i asked that question. your answer somehow pops in my mind but i need somebody who can clarify it and you did. tnx!