Simplify the following text for a Grade 10 native English-speaking person.
Original: On 14 May 2006 , the five GPMA-backed teams signed a Memorandum of Understanding with the commercial rightsholders ( CVC\/Ecclestone ) which formed the basis of the next Concorde Agreement .
Simplified: On 14 May , 2006 , the five GPMA-backed teams signed a Memorandum of Understanding ( a letter agreeing to the terms ) with the commercial rights holders ( CVC\/Ecclestone ) . This formed the basis of the next Concorde Agreement .