A social law, which stipulates that

When referencing a particular item when there is an acceptable standard, using a general name will suffice as a request for that specific standard.

Putting this in practice will eliminate one of my pet peeves:

A person walks into a store and asks "Could I have a pack of M&M's?" The clerk turns and is faced with rows of M&M's, flavoured Plain, Almond, Peanut, Peanut Butter, Crunchy, et al. Which should he choose? This may prove to be an interesting dilemma, and the clerk may ask the customer for his preference.
"What type?"
The customer then kills the clerk for incompetence.

How can this situation have been avoided? Simple: Enact the M&M law of simplicity. In this case, there is an acceptable standard. Right on the packet of M&M's it says "Plain", obviously the standard, if not the most common, of the M&M's. Using a general name, (in this case "M&M's") will suffice to deduce that this acceptable standard should be presented to the customer. It is the customer's responsibility to specify alternate types, if what he desires is not the acceptable standard.
In the same way, "Skittles" refers to "Original Fruit" or "red" Skittles; "Coke" refers to "Coca-Cola Classic".

There are opponents to this law who might claim the following:
"'Coke' has become a term for any cola in passing, in much the same way 'Tylenol' is now relatable to any brand of 'acetaminophen'. If someone asks for 'Tylenol' and you have 'Ken's Brand Acetaminophen' there will be no complaints. In the same way, in viewing a fridge full of cola, one might say 'Pass me a Coke'."
This then leads to the following situation:
Customer: Can I have a Coke?
Ten minutes pass. Waitress returns with drink.
Customer: What is this?
Waitress: Pepsi.
This will result in the waitress receiving no tip. The reason is this exception to the rule:

The M&M law of simplicity can only be enacted in a situation in which there is either no brand loyalty, or a distinct acceptable standard.

In the case of Coke/Pepsi, neither condition is met. There is definitely evidence of brand loyalty, and no clear acceptable standard between the two. This situation is thus not covered by the M&M law of simplicity.