As per the answer given to this question, AN 3.87 was cited as such:
...Having undertaken the training rules, he trains in them. With the utter destruction of three fetters, he is a seven-times-at-most attainer who, after roaming and wandering on among devas and humans seven times at most, makes an end of suffering;
With the utter destruction of three fetters, he is a family-to-family attainer who, after roaming and wandering on among good families two or three times, makes an end of suffering;
With the utter destruction of three fetters, he is a one-seed attainer who, after being reborn once more in human existence, makes an end of suffering.
I'm not able to find an English translation of this sutta online, but the individual who posted this said that the third individual described, a "one-seeder", is actually not a Sakadagami, but an Ekabiji, the highest degree of Sotapanna? And the first two are lower degrees of Sotapanna. Does anyone have any insight into this? I was unaware that there were varying degrees of stream-winners. Thank you.