Hi, I'm a graduate student from China who has been in the US as F1 for more than 5 years but less than 6. I was told that I'm considered a "resident" now and should file 1040 instead of 1040NR. Moreover, I should claim my treaty benefit as "other income" in Line 21 in 1040 and should file 8833 for this purpose. I know the treaty article for me (currently research assistant) is 20(b). However, the line 2,4, and 5 in 8833 really confuse me. Could you please explain what is "Internal Revenue Code" provision and what should I put in those lines? Thank you very much!

Read the instructions of the form carefully. You have to find the portion of the Internal Revenue Code that requires you pay taxes on W-2 income; that is the part of the IRC you are trying to over-wide in claiming the treaty exemption.