bobad - I'm glad you have a son that is exploring the rules of written language. The fact that he noticed the anomoly, speaks volumes for his curiosity and interest. It also speaks well of you as a parent.

When I read the original post, I knew that Dr was right but did not agree with the explanation given by the company.

I think you can chalk it up to 'commercial license'.

Same reason we have words like X-mas.

Dr isn't really an abbreviation because their isn't really a doctor in this instance. Its just a brand name.