1974 XLCH - vent line from oil tank question

[IrishDavey]

I have a 1974 XLCH with the original square oil tank. I have the oil feed and return lines hooked up to the bottom of the tank. All is good, everything runs as expected.
Now I have a third hose, described on page 3-5 of the service manual as "15. Vent line from oil tank". Herein lies the problem. Currently I have it venting to the world, and when the engine is running it spits out little drops of oil, not a lot. However, my oil tank only has fittings for hose connections on the bottom of the tank, one of which is currently plugged. It doesn't seem right that a vent hose should connect to the bottom of the tank, where gravity will cause oil to flow down into the engine, thus blocking any venting.
Can anybody tell me how this came from the factory? Or whether hooking the vent to the tank bottom is correct? Or what a good solution is?
Thanks.

[Dragstews]

The oil tank has to vent ....

When oil gets hot it expands, also with the pump moving oil in and out air bubbles gets mixed in...
Pressure would build up not having anywhere to go...

What Harley did was a close system by venting the tank back to the motor...
They could have done a vent at the top of the tank, but that would be a route for oil to make it's way into the environment .... Green Peace would be on them like ugly on a Ape !!!!

Yes, the vent needs to be at the very top of the tank as with the return line, feed line at the bottom....

[IrishDavey]

Thanks.
I have also been informed that although the return and vent connections to the tank are on the bottom, there are internal tubes that end above the oil level in the tank thus allowing the case vent to 'air'. I'm also told the feed has a different size nipple to the vent and return lines. I think the return is 1/8" npt to 3/8" , I'm guessing the vent is the same.
I guess I'll pull the tank Friday, and install the hose fitting.