  Corporate networks, as induced by interlocking directorates between
corporations, provide structures of personal communication at the level of
their boards. This paper studies such networks from a perspective of close
communication in sub-networks, where each pair of nodes (boards of a
corporation) are either neighbours, or have a common neighbour. These
correspond to subgraphs of diameter at most 2, designated by us earlier as
2-clubs, with three types (coteries, social circles and hamlets) as degrees of
close communication in social networks, within the concept of boroughs of a
network. Boroughs are maximal areas and containers of close communication
between nodes of a network. This framework is applied in this paper to an
analysis of corporate board interlocks between the top 300 European
corporations 2010, as studied by Heemkerk (2013), with data provided by him for
that purpose. The paper gives results for several perspectives of close
communication in the European corporate network of 2010, a year close to the
global crash of 2008, as a further elaboration of those given in Heemskerk
(2013).
