This informal protocol declares several methods that are used to perform common comparisons between two objects. In Cocoa's scripting system, comparisons are represented by instances of NSSpecifierTest, which relies on objects implementing either methods from this protocol, or the NSScriptingComparisonMethods protocol.

@interface NSObject (NSComparisonMethods)
// Instance Methods
- (BOOL)isEqualTo:(id)object;
- (BOOL)isLessThanOrEqualTo:(id)object;
- (BOOL)isLessThan:(id)object;
- (BOOL)isGreaterThanOrEqualTo:(id)object;
- (BOOL)isGreaterThan:(id)object;
- (BOOL)isNotEqualTo:(id)object;
- (BOOL)doesContain:(id)object;
- (BOOL)isLike:(NSString *)object;
- (BOOL)isCaseInsensitiveLike:(NSString *)object;
@end