  In the paper [3] the value of the invariant denoted by d and often called
"rank" was misstated for a narrow class of examples of ECS manifolds: they were
identified as having d = 1 instead of the correct value d = 2. The error was
repeated, by citing [3], in [1], [2] and [4] -- [7]. We briefly describe the
class in question, explain why it has d = 2, and list the required corrections
of the affected papers.
