stringWithString question

[Rob Burns]

NSString str = [NSString stringWithString: @"\10, 11, 12, 13"];

If I have that line of code, the first character of str will be a 
comma. if I add another backslash at the beginning, the first 
character of str will be a backslash. I would expect that behaviour 
for stringWithFormat: But, should escaping the backslash be necessary 
when using stringWithString?

Thanks
Rob