From my understanding, some of the previous posts have bits and pieces of the answer. Daito-ryu has several classifications with numerous techniques within each class {ikkajo, nikajo, sankajo, etc..}. O'Sensei took several techniques from each classification when making Aikido. Some of the techniques names were changed while some were kept the same. Ikkyo is Ippon dori in Daito-ryu and Nikyo is Shuto zume while Kotegaeshi remained the same as examples. I think O'Sensei gave the names to the techniques for Saito Sensei and Ichidai Doshu has the same name for the techniques but they didn't practice together. One being in Iwama while the other being in Tokyo.