  The u-invariant of a field is the supremum of the dimensions of anisotropic
quadratic forms over the field. We define corresponding u-invariants for
hermitian and generalised quadratic forms over a division algebra with
involution in characteristic 2 and investigate the relationships between them.
We also investigate these invariants in the case of a quaternion algebra and in
particular when this quaternion algebra is the unique quaternion division
algebra over a field.
