[1] Likewise or similarly in other lexica; references at Photius tau118 Theodoridis.
[2] The distinction between 'proof' and 'sign' is Aristotle's (see Rhetoric 1357b1-20). A similar distinction regarding signs can be found in Sextus Empiricus (Outlines of Pyrrhonism 2.100; 102: when one sees smoke, one has a sign that there was fire). The claim that a sign is refutable and a proof irrefutable belongs to Aristotle, who regards proof as being a species of the genus 'sign': "among signs, one [kind of sign] is like the particular with regard to the universal; for example, if one said that there is a sign that the wise are just. For Socrates was wise and just. Certainly, this is a sign, but it is refutable, even though what was said is true. For it is not deductively conclusive. By contrast, this [sign] is necessary: if one said that there is a sign that [this person] is sick for he has fever, or [that there is a sign] that [this woman] has given birth because she has milk. Among the signs, just this is a proof, for it is the only one that it is irrefutable" (Rhetoric 1357b10-17).
[3] John Philoponus, Commentary on Aristotle's de anima 31.16-20 Hayduck; cf. alpha 3289.
[4] Procopius, Secret History 18.1-2 (web address 1); cf. Kaldellis (80-81). The Suda has mistakenly added 'Theodora' to the Procopius excerpt; the source text concerns her husband Justinian, not the empress. On Justinian's demonic nature, see also alpha 1259, delta 806, epsiloniota 225, iota 726, and pi 2088. For Theodora see alpha 956 note.
[5] Damascius, Life of Isidore fr. 74 Zintzen (32 Asmus); cf. omicron 644.
[6] Cassius Dio 68.17.2.