[Closed] question about a replacement road chainring.

Hi,
Ive just fitted a 52 tooth chainring to replace the 50 that came standard with my road bike. The one ive taken off has one round lug that stands proud of the chainring (by about half an inch) on the inside, and the new chainring has come supplied with a bolt which clearly does the same job. Ive seen chainrings where a bolt or lug like this fits onto the crank arm to hold it (like on a bmx spider), but on my roadbike it doesnt seem to serve any purpose as the ring doesnt connect to the crank at any point except the 5 recessed allen bolts. Do i need to fit this, and if i do, do i need to align the chainring so that this lug is hidden behind the crank arm? My guess is that if theyve supplied it and the chainring i took off had one, that i should fit it, but typically i didnt pay attention when i took the old one off and im not sure where its supposed to point!! cheers in advance for any help, simon.