Using comma's with a single conjuction of three or more terms.

When comparing three or more terms one should seperate them by comma's:

• dog, cat, and bird
• green, white, and black

This applies to the following as well:

• mild, hot, or on fire

Make sure one does not forget the comma after multiple terms:

• Tammie, Vickie, James, John, Collin, and Tony

As for business firms the usage for comma's is a little different. For example,

• Green, White and Company--correct
• Tom, Jane & Ben --correct
• Williams, Smith, and Blake--wrong
• no comma after Smith