tripper1000:

 

IMHO they shouldn't have 110 and 110A. It should be 110A and 110B - way less room for confusion. 

 

As someone recently subdivided and now lives in a 6A, I can understand why it's done the way it is. Our 6A is a recent subdividion from a number 6 (owned by by parent in law) originally assigned when the street and houses were built in the 1970s. If we subdivided the 6 to a 6A/6B my PIL would have had their old address invalidated and forced to change all their addresses from 6 to 6A. At least this way the original house keeps the original number 6 and only the new house gets a new address i.e. 6A. A good example of something that seems silly on the surface but when you dig deeper it makes sense.