It should be A, Because I said so..
"An Istoric"?? what is that? the only way that is right is if you have a head cold and your nose is plugged up. The english language has been butchered up by a bunch of people who "THINK" something is acceptable, or who think its cool, or neat to be different.
If the word begins with any other sound than that produced by the letters A, E, I, O, and U, then it should be A. An is reserved for applications where the double vowel sound makes it difficult to pronounce.
What is accepted, and what is correct are two very different things...
A hoe, is a garden tool...
Shizzle is NOT a word!
History is pronounced History...
Hour is pronounced Our..
O'rly? means nothing...
And Probably is not spelled Prolly....
We are in a text message crazed era, its its going to destroy us all, Soon we'll all be drawing deer on the walls of our caves with pointed rocks... and eating spit fire cooked rabbits....