An UDF (user-defined field) is 'created' globally, but applied individually. Other contact mgrs, i.e. GoldMine or ACT, apply a user field globally, which means, if you create a field, it is now connected to each record in the database.
Maximizer does not work this way. You create the UDF, specifying whether it is a Company, Individual, Contact UDF or a combination. However the UDF is not attached to a record until a specific action is taken.
You might want to look in Help for more info on how UDF's work.