For ostracism see OCD4 s.v. and already omicron 716. (In the Vaticanus 1296 ms, in fact, 716 and 717 form a single entry.) LSJ entries at web addresses 1 & 2.
[1] So again phi 812.
[2] Time: leave within 10 days and stay away 10 years (after which return/rehabiliation was possible and legitimate: witness Kimon, about to be mentioned, who left Athens in 461 BCE and returned -- to favour and to office -- in 451). Place: between 481/0 and an indeterminable date thereafter (perhaps not long after, if this was a Persian-War emergency measure) the ostracized had not merely to leave Athens but stay well outside it. See ?Aristotle, Athenaion Politeia 22.8, with P.J. Rhodes, A Commentary on the Aristotelian Athenaion Politeia (Oxford 1981) 282; T.J. Figueira, GRBS 28 (1987) 281-305.
[3] From the scholia to Aristophanes, Wasps 947, where Thoukydides the 'exile' (in fact he was ostracized) is mentioned.
[4] So already alpha 3563 and kappa 1621; see the note to the latter.