Mentioned in IG XII.5 608 line 9, discussed in Schmidt, D. (1999), 'An Unusual Victory List from Keos: IGXII.5.608 and the Dating of Bacchylides', JHS 119, 67-85, p.70. I follow Farrington (2012), no. 1.41 and p. 113-4 note 252. Farrington suggests Ioulis, perhaps Keos as the origin of the victor, since that is where the inscription, a victory list likely pertaining to Isthmian victors (Farrington (2012), p. 113 note 249), was found (from l. 17 onward it pertains to Nemean victories). Farrington's note 252 pertains to the dating, which he based upon the estimated addition of age category ageneioi to the Isthmian games.
Phaidippes was Liparion's brother: he won on the same day as his brother in the Isthmian Games, Liparion as an aner and Phaidippes as an ageneios. Discipline is illegible - Farrington suggests pankration. - PK