Simplify the following text for a Grade 8 native English-speaking person.
Original: Ultratop 50 singles , often just Ultratop 50 , is the weekly chart of fifty best-selling singles in Flanders , Belgium , and is produced and published by the Ultratop organization .
Simplified: Ultratop 50 singles , often called Ultratop 50 , is the weekly chart of fifty best-selling singles in Flanders , Belgium . Ultratop 50 and is produced and published by the Ultratop organization .