The value for the NSGrammarUserDescription dictionary key should be an NSString containing descriptive text about that range, to be presented directly to the user; it is intended that the user description should provide enough information to allow the user to correct the problem. It is recommended that NSGrammarUserDescription be supplied in all cases, however, NSGrammarUserDescription or NSGrammarCorrections must be supplied in order for correction guidance to be presented to the user.
Available in Mac OS X v10.5 and later.
Declaration Syntax Version Information- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)