why both tapered pin and regular pin with hyperglide chain?

I've never bought one from the net or lbs that came with both types of pins. Lbs ultegra chains have been Shimano packaged with 2 tapered pins. The ones I've bought from pbk have been either Shimano packaged with tapered pins or oem with the 'pin sticking out of the link'
If you didn't get an instruction sheet which usually only comes with a Sh.. pack.. What it says with regard the short pin is-
"Black connecting pins pre-attached to the outer link (supplied only to the OEMs) can be assembled using Shimano chain tools. The assembly method should be the same as using standard reinforced connecting pins."

Thanks for the reply. It's for a special tool, I guess.

My instructions picture a conventional pin sticking out of the end side plate but offer no mention about what to do with it.

many years ago we believed that is was only there to hold the chain together on the bike while you get the right pin ready and it is driven out when you install the correct 'break off' pin...

anyone?

all's'miles

curby