What are Altera BSDL instructions 2,3 and 4?

I am looking at an .svf programming file created by Quartus 13.2 and trying to understand what each SIR instruction does. Unfortunately I can't find any documentation for:

SIR 10 TDI (002);

which should mean load the instruction register with 10 bit hex value 0x002. The same question goes for instruction 3 and 4.

Can anyone tell me what these instructions do?