Fuel line question

Does anyone happen to know which line is for which on top of a 98+ fuel pump? I can tell which is the outlet and which is the vent. But what is the 3rd one for? I took my fuel system apart 3 years ago and couldn't remember if I wanted to.

I know the 98+ Rangers have returnless systems so I just planned on venting it off the fucl pump and capping my fuel cell. And running my fuel lines right to the motor, with a checkvavle and filter inline by the tank and the inline sensor thing.....

Is there anything else I should worry about? Should I just cap the 3rd line on the fuel pump?

doesn't the 98+ rangers have a charcoal canister hooked up to the gas tank?

yep the 98s+ have that canister on them. mines un hooked right now but id prolly hook it back up because im sure it does something or ford wouldnt have put it on there. and with it un hooked, my truck acts kinda funny with a FULL tank of gas. i dont know, what the hell