This is a sentence from Wikipedia:
The Chevrolet Corvette , known colloquially as the Vette or Chevy Corvette , is a sports car manufactured by Chevrolet.
Is the placement of comma before known and is correct?
When we have to give additional info about a noun, we place commas to enclose the phrase, e.g. "Saraswati, the goddess of knowledge, is..."
But somehow, here, its usage seems wrong to me; especially the one before is. What's the rule to be followed for such cases?