“…3]. In [30,Corollary 3.8] it is proved: For q even, the set Ω2 in Grüning's unital ( [17], see [14, 5.5] for the description needed here) has size q + 1, and that unital admits exactly q + 1 non-trivial translations, each of order 2. In [30, 4.6, 4.7, 4.8] one finds unitals of order 4 with no translations, unitals of order 4 with |Ω2| = 1 and Γ [2] ∼ = C2, and unitals of order 4 with |Ω2| = 1 and Γ [2] ∼ = C2 × C2.…”