Wikipedia says that the US and Canada use letter size paper and the rest of the world uses A4 and that some countries use both. I want to create a PDF in my iPad application and am trying to figure out a clean way to determine whether to set my bounds to letter or A4. I am also looking for any common patterns used to let someone change from one size to the other.
I have already looked at this Stackoverflow question to get some of the basics down with region checking.
So, my question rephrased as a question: is there any way other than checking to see what region and then assuming that US/Canada are letter to know the user's preferred default paper size?