All error codes are numbers, but different APIs’ numbers can overlap. An NSError “domain” is a set of non-overlapping numbers. Carbon uses NSOSStatusErrorDomain.

No error is indicated by noErr, which is 0.

Error codes from 1000-9999 are for applications’ internal use.

Some lists:

Almost all Carbon codes�MacErrors.h* *Unlisted old Carbon codes�http://developer.apple.com/documentation/macos8/ResultCodeTable/ResultCodes.pdf *Finder codes�http://developer.apple.com/documentation/Carbon/Reference/Finder_Interface/finder_interface/constant_3.html