It all depends on context. Take a contract to order 32 blue white and red sweaters at a total cost of $200. You could potentially end up with:
- 32 sweaters that contain all three colors.
- 32 sweaters of each color. (total of 96 sweaters)
- 32 blue sweaters and 32 white and red sweaters. (total of 64 sweaters)
With or without a comma that is just ambiguous, which is really what is to be avoided at all costs in legal documents. If I were the manufacturer of the sweaters it would be cheapest to just send you the least amount of sweaters. If you meant either of the other two you get shorted at least 32 sweaters, not to mention the ones you receive aren't the correct color combination.
The signed contract is considered to be the final copy, as it is signed, witnessed, etc. Just because you discussed what the ambiguous clause meant does not necessarily mean that the court will enforce that, as it is hard to prove.