[1] du/namai is a deponent verb, and this theoretical active form du/nhmi is attested only in lexicographic texts, e.g. Etymologicum Magnum and Etymologicum Gudianum, always in explanation of du/namai. In Etym.Magn. 290.24 (probably taken from Choeroboscus’ commentaries on the Psalms) the same verb is glossed in the subjunctive mood, as here, but in the third person plural: "du/nwntai: from du/nhmi: from which [come] the passive du/namai; the subjunctive, e)a\n du/nwmai. And it should be e)a\n dunw=mai, like tiqw=mai, but there is a rule saying that a -mi verb is properispomenon in the subjunctive [middle-passive], whenever the present [active] form occurs in practice: e.g. ti/qhmi, e)a\n tiqw=mai, i(/sthmi, e)a\n i)stw=mai. But when this form does not occur in practice, then [in the middle-passive form] it is proparoxytone: e.g. du/nhmi, e)a\n du/nwmai, for du/nhmi does not occur in practice. And the plural [is] du/nwntai." Here Etym.Magn. seems not to take into account -numi verbs, which are proparoxytone in the subjunctive middle/passive voice: e.g. dei/knumi, subjunctive deiknu/wmai.
[2] Perispomenon: a word with circumflex accent on the last syllable: verbs that are perispomenon in the active voice are what we call contract verbs.
[3] Properispomenon: a word with circumflex accent on the penult. Nonetheless there is at least an exception for the second person singular, which is perispomenon also in the middle-passive form.
[4] Proparoxytone: a word with acute accent on the antepenult.
[5] Even if not explicitly as in Etymologicum Magnum, the compiler is recognising that the form du/nhmi does not exist in practice; cf. n.1 above.
[6] Homer, Iliad 14.196 (with the participle tetelesme/non translated according to G. Autenrieth: see web address 1 below), followed by Aristonicus’ scholion on the line.