This
release on PostgreSQL.org describes an ongoing disagreement over the
PostgreSQL trademark:
In 2020, the PostgreSQL Core Team was made aware that an
organization had filed applications to register the ‘PostgreSQL’
and ‘PostgreSQL Community’ trademarks in the European Union and the
United States, and had already registered trademarks in Spain. The
organization, a 3rd party not-for-profit corporation in Spain
called ‘Fundación PostgreSQL,’ did not give any indication to the
PostgreSQL Core Team or PGCAC that they would file these
applications.