Slider pins

[Mickswan]

I'm just putting together my callipers, however one of the slider pins on each calliper has an anti rattle boot on the end of the pin (see poor picture).

http://i1280.photobucket.com/albums/a496/MickSwan/image_zps2c75dcc3.jpg (http://s1280.photobucket.com/user/MickSwan/media/image_zps2c75dcc3.jpg.html)

How do I tell which pin goes in where?