that campag use different sized (smaller) nipples on their gear cables. If your shifters are campag, use campag cables. The danger is the larger Shimano and after market cable nips get stuck in the shifter recess, giving you grief when replacing them.
It sez 'ere what I've heard from a good LBS;
http://answers.wiggle.co.uk/answers/7867-en_gb/product/5360009232/ergopower-gear-and-brake-cable-set-questions-answers/questions.htm
that campag use different sized (smaller) nipples on their gear cables. If your shifters are campag, use campag cables. The danger is the larger Shimano and after market cable nips get stuck in the shifter recess, giving you grief when replacing them.