Overgroups of classical groups over commutative rings in linear group. (Q862709)

For any commutative ring \(R\) with involution and 1, unitary groups \(\text{U}_{2n}R\subset\text{GL}_{2n}R\) (including symplectic, ordinary orthogonal, and standard unitary groups) are considered. All overgroups of \(\text{U}_{2n}R \) are described when \(n\geq 5\). The classification of normal subgroups of \(\text{U}_{2n}R,\) obtained previously by You-Vaserstein, is used.