Instead of overriding class initializers, consider overriding the new methods. There's only one default 'new' method, which makes autocompletion of your own custom ones a lot easier.

Person.h

/** A person, with a name. */
@interface Person : NSObject

/** Creates a new person with the specified name. */
+ (id)newWithString:(NSString *)name;

@end

Person.m

@implementation Person

{
    NSString *_name;
}

+ (id)newWithString:(NSString *)name
{
    return [[self alloc] initWithName:name];
}

- (id)initWithName:(NSString *)name
{
    NSParameterAssert(name);
    self = [super init];
    if (self) {
        _name = name;
    }
    return self;
}

- (id)init
{
    // Asserting this to always fail also makes a lot of sense.
    // Might do that in the future.
    
    NSLog(@"Don't use the default initializer. Use +newWithName: instead.");
    return nil;
}

@end