Name for %@ %d in an NSString

Question

What are these called in Objective C? @"%@" @"%d" @"%i"

Answer 1

They are called format specifiers, could also be called 'placeholders in a string for the variables that will follow'.

https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Strings/Articles/formatSpecifiers.html

Answer 2

They are NSString literals. More specifically, they look they are being used as formatting strings for printf style functions.