PostgreSQL tables in a schema

Is it possible to place the necessary tables in a separate schema? We need to cross-reference some tables and it would be very convenient if we could place the tables inside the same database together with our other schemas. I saw that same table names are specified in the configuration file (postgresql.conf). Probably it would be easy to prepend the schema name. But I saw some other tables in the DB that are not mentioned in the conf file. -- Milen A. Radev