Refer to advertisemnt, wherein it is written that, A candidate may apply for two posts, prescribed in each form for BPS16 and below, subject to eligiblity by paying single fee.

Can someone pl elaborate this?
For Example i have to apply for Assisstant (BPS15), Sub Inspector (BPS-14), Traffic Analyst (BS-14), Upper Division Clerk (BS-11), then how many forms and fees would i have to submit?